diff --git a/app/BUILD.bazel b/app/BUILD.bazel
index caf40076824..1d76b8de251 100644
--- a/app/BUILD.bazel
+++ b/app/BUILD.bazel
@@ -648,6 +648,7 @@ kt_android_library(
         "//third_party:androidx_databinding_databinding-runtime",
         "//utility",
         "//utility/src/main/java/org/oppia/android/util/extensions:context_extensions",
+        "//utility/src/main/java/org/oppia/android/util/logging/firebase:debug_event_logger",
         "//utility/src/main/java/org/oppia/android/util/logging/firebase:debug_module",
         # TODO(#59): Remove 'debug_util_module' once we completely migrate to Bazel from Gradle as
         # we can then directly exclude debug files from the build and thus won't be requiring this module.
diff --git a/app/src/main/java/org/oppia/android/app/help/HelpActivity.kt b/app/src/main/java/org/oppia/android/app/help/HelpActivity.kt
index 74933ebcdfc..25d53ed8946 100644
--- a/app/src/main/java/org/oppia/android/app/help/HelpActivity.kt
+++ b/app/src/main/java/org/oppia/android/app/help/HelpActivity.kt
@@ -14,7 +14,6 @@ import org.oppia.android.app.help.thirdparty.ThirdPartyDependencyListActivity
 import org.oppia.android.app.translation.AppLanguageResourceHandler
 import org.oppia.android.util.extensions.getStringFromBundle
 import javax.inject.Inject
-import kotlin.properties.Delegates
 
 const val HELP_OPTIONS_TITLE_SAVED_KEY = "HelpActivity.help_options_title"
 const val SELECTED_FRAGMENT_SAVED_KEY = "HelpActivity.selected_fragment"
@@ -45,8 +44,6 @@ class HelpActivity :
 
   private lateinit var selectedFragment: String
   private lateinit var selectedHelpOptionsTitle: String
-  private var selectedDependencyIndex by Delegates.notNull<Int>()
-  private var selectedLicenseIndex by Delegates.notNull<Int>()
 
   override fun onCreate(savedInstanceState: Bundle?) {
     super.onCreate(savedInstanceState)
@@ -57,9 +54,9 @@ class HelpActivity :
     )
     selectedFragment =
       savedInstanceState?.getStringFromBundle(SELECTED_FRAGMENT_SAVED_KEY) ?: FAQ_LIST_FRAGMENT_TAG
-    selectedDependencyIndex =
+    val selectedDependencyIndex =
       savedInstanceState?.getInt(THIRD_PARTY_DEPENDENCY_INDEX_SAVED_KEY) ?: 0
-    selectedLicenseIndex = savedInstanceState?.getInt(LICENSE_INDEX_SAVED_KEY) ?: 0
+    val selectedLicenseIndex = savedInstanceState?.getInt(LICENSE_INDEX_SAVED_KEY) ?: 0
     selectedHelpOptionsTitle = savedInstanceState?.getStringFromBundle(HELP_OPTIONS_TITLE_SAVED_KEY)
       ?: resourceHandler.getStringInLocale(R.string.faq_activity_title)
     helpActivityPresenter.handleOnCreate(
diff --git a/app/src/main/java/org/oppia/android/app/help/HelpActivityPresenter.kt b/app/src/main/java/org/oppia/android/app/help/HelpActivityPresenter.kt
index 185c3913b48..7c2debc1189 100644
--- a/app/src/main/java/org/oppia/android/app/help/HelpActivityPresenter.kt
+++ b/app/src/main/java/org/oppia/android/app/help/HelpActivityPresenter.kt
@@ -18,7 +18,6 @@ import org.oppia.android.app.help.thirdparty.LicenseTextViewerFragment
 import org.oppia.android.app.help.thirdparty.ThirdPartyDependencyListFragment
 import org.oppia.android.app.translation.AppLanguageResourceHandler
 import javax.inject.Inject
-import kotlin.properties.Delegates
 
 /** The presenter for [HelpActivity]. */
 @ActivityScope
@@ -31,8 +30,8 @@ class HelpActivityPresenter @Inject constructor(
 
   private lateinit var selectedFragmentTag: String
   private lateinit var selectedHelpOptionTitle: String
-  private var selectedDependencyIndex by Delegates.notNull<Int>()
-  private var selectedLicenseIndex by Delegates.notNull<Int>()
+  private var selectedDependencyIndex: Int? = null
+  private var selectedLicenseIndex: Int? = null
 
   fun handleOnCreate(
     helpOptionsTitle: String,
@@ -60,7 +59,7 @@ class HelpActivityPresenter @Inject constructor(
     val titleTextView =
       activity.findViewById<TextView>(R.id.options_activity_selected_options_title)
     if (titleTextView != null) {
-      setMultipaneContainerTitle(helpOptionsTitle!!)
+      setMultipaneContainerTitle(helpOptionsTitle)
     }
     val isMultipane = activity.findViewById<FrameLayout>(R.id.multipane_options_container) != null
     if (isMultipane) {
@@ -140,8 +139,8 @@ class HelpActivityPresenter @Inject constructor(
       outState.putString(HELP_OPTIONS_TITLE_SAVED_KEY, titleTextView.text.toString())
     }
     outState.putString(SELECTED_FRAGMENT_SAVED_KEY, selectedFragmentTag)
-    outState.putInt(THIRD_PARTY_DEPENDENCY_INDEX_SAVED_KEY, selectedDependencyIndex)
-    outState.putInt(LICENSE_INDEX_SAVED_KEY, selectedLicenseIndex)
+    selectedDependencyIndex?.let { outState.putInt(THIRD_PARTY_DEPENDENCY_INDEX_SAVED_KEY, it) }
+    selectedLicenseIndex?.let { outState.putInt(LICENSE_INDEX_SAVED_KEY, it) }
   }
 
   private fun setUpToolbar() {
@@ -156,7 +155,13 @@ class HelpActivityPresenter @Inject constructor(
       val currentFragment = getMultipaneOptionsFragment()
       if (currentFragment != null) {
         when (currentFragment) {
-          is LicenseTextViewerFragment -> handleLoadLicenseListFragment(selectedDependencyIndex)
+          is LicenseTextViewerFragment -> {
+            handleLoadLicenseListFragment(
+              checkNotNull(selectedDependencyIndex) {
+                "Expected dependency index to be selected & defined"
+              }
+            )
+          }
           is LicenseListFragment -> handleLoadThirdPartyDependencyListFragment()
         }
       }
diff --git a/app/src/sharedTest/java/org/oppia/android/app/player/state/StateFragmentTest.kt b/app/src/sharedTest/java/org/oppia/android/app/player/state/StateFragmentTest.kt
index 7a6d9942f7e..6c0917f22b4 100644
--- a/app/src/sharedTest/java/org/oppia/android/app/player/state/StateFragmentTest.kt
+++ b/app/src/sharedTest/java/org/oppia/android/app/player/state/StateFragmentTest.kt
@@ -2603,6 +2603,7 @@ class StateFragmentTest {
     targetTextViewId: Int
   ) {
     scrollToViewType(SELECTION_INTERACTION)
+    // First, check that the option matches what's expected by the test.
     onView(
       atPositionOnView(
         recyclerViewId = R.id.selection_interaction_recyclerview,
diff --git a/app/src/test/java/org/oppia/android/app/player/state/StateFragmentLocalTest.kt b/app/src/test/java/org/oppia/android/app/player/state/StateFragmentLocalTest.kt
index f7e45747c30..dc0ff28e020 100644
--- a/app/src/test/java/org/oppia/android/app/player/state/StateFragmentLocalTest.kt
+++ b/app/src/test/java/org/oppia/android/app/player/state/StateFragmentLocalTest.kt
@@ -17,6 +17,7 @@ import androidx.test.espresso.PerformException
 import androidx.test.espresso.ViewAction
 import androidx.test.espresso.ViewAssertion
 import androidx.test.espresso.action.ViewActions.click
+import androidx.test.espresso.assertion.ViewAssertions.doesNotExist
 import androidx.test.espresso.assertion.ViewAssertions.matches
 import androidx.test.espresso.contrib.RecyclerViewActions.scrollToHolder
 import androidx.test.espresso.contrib.RecyclerViewActions.scrollToPosition
@@ -33,6 +34,8 @@ import com.bumptech.glide.GlideBuilder
 import com.bumptech.glide.load.engine.executor.MockGlideExecutor
 import com.google.common.truth.Truth.assertThat
 import dagger.Component
+import dagger.Module
+import dagger.Provides
 import kotlinx.coroutines.CoroutineDispatcher
 import org.hamcrest.BaseMatcher
 import org.hamcrest.CoreMatchers.allOf
@@ -69,11 +72,13 @@ import org.oppia.android.app.player.state.itemviewmodel.StateItemViewModel.ViewT
 import org.oppia.android.app.player.state.itemviewmodel.StateItemViewModel.ViewType.CONTINUE_NAVIGATION_BUTTON
 import org.oppia.android.app.player.state.itemviewmodel.StateItemViewModel.ViewType.FRACTION_INPUT_INTERACTION
 import org.oppia.android.app.player.state.itemviewmodel.StateItemViewModel.ViewType.NEXT_NAVIGATION_BUTTON
+import org.oppia.android.app.player.state.itemviewmodel.StateItemViewModel.ViewType.NUMERIC_INPUT_INTERACTION
 import org.oppia.android.app.player.state.itemviewmodel.StateItemViewModel.ViewType.PREVIOUS_RESPONSES_HEADER
 import org.oppia.android.app.player.state.itemviewmodel.StateItemViewModel.ViewType.SELECTION_INTERACTION
 import org.oppia.android.app.player.state.itemviewmodel.StateItemViewModel.ViewType.SUBMIT_ANSWER_BUTTON
 import org.oppia.android.app.player.state.testing.StateFragmentTestActivity
 import org.oppia.android.app.recyclerview.RecyclerViewMatcher
+import org.oppia.android.app.recyclerview.RecyclerViewMatcher.Companion.atPositionOnView
 import org.oppia.android.app.shim.ViewBindingShimModule
 import org.oppia.android.app.topic.PracticeTabModule
 import org.oppia.android.app.translation.testing.ActivityRecreatorTestModule
@@ -113,6 +118,7 @@ import org.oppia.android.testing.OppiaTestRule
 import org.oppia.android.testing.RunOn
 import org.oppia.android.testing.TestLogReportingModule
 import org.oppia.android.testing.data.DataProviderTestMonitor
+import org.oppia.android.testing.environment.TestEnvironmentConfig
 import org.oppia.android.testing.espresso.EditTextInputAction
 import org.oppia.android.testing.espresso.KonfettiViewMatcher.Companion.hasActiveConfetti
 import org.oppia.android.testing.espresso.KonfettiViewMatcher.Companion.hasExpectedNumberOfActiveSystems
@@ -126,7 +132,10 @@ import org.oppia.android.testing.threading.TestDispatcherModule
 import org.oppia.android.testing.time.FakeOppiaClockModule
 import org.oppia.android.util.accessibility.AccessibilityTestModule
 import org.oppia.android.util.caching.AssetModule
-import org.oppia.android.util.caching.testing.CachingTestModule
+import org.oppia.android.util.caching.CacheAssetsLocally
+import org.oppia.android.util.caching.LoadImagesFromAssets
+import org.oppia.android.util.caching.LoadLessonProtosFromAssets
+import org.oppia.android.util.caching.TopicListToCache
 import org.oppia.android.util.gcsresource.GcsResourceModule
 import org.oppia.android.util.locale.LocaleProdModule
 import org.oppia.android.util.logging.LoggerModule
@@ -251,7 +260,7 @@ class StateFragmentLocalTest {
     launchForExploration(FRACTIONS_EXPLORATION_ID_1).use {
       startPlayingExploration()
 
-      playThroughState1()
+      playThroughFractionsState1()
 
       onView(withId(R.id.hint_bulb)).check(matches(not(isDisplayed())))
     }
@@ -261,7 +270,7 @@ class StateFragmentLocalTest {
   fun testStateFragment_nextState_wait10seconds_noHintAvailable() {
     launchForExploration(FRACTIONS_EXPLORATION_ID_1).use {
       startPlayingExploration()
-      playThroughState1()
+      playThroughFractionsState1()
 
       testCoroutineDispatchers.advanceTimeBy(TimeUnit.SECONDS.toMillis(10))
 
@@ -273,7 +282,7 @@ class StateFragmentLocalTest {
   fun testStateFragment_nextState_wait30seconds_noHintAvailable() {
     launchForExploration(FRACTIONS_EXPLORATION_ID_1).use {
       startPlayingExploration()
-      playThroughState1()
+      playThroughFractionsState1()
 
       testCoroutineDispatchers.advanceTimeBy(TimeUnit.SECONDS.toMillis(30))
 
@@ -285,7 +294,7 @@ class StateFragmentLocalTest {
   fun testStateFragment_nextState_wait60seconds_hintIsAvailable() {
     launchForExploration(FRACTIONS_EXPLORATION_ID_1).use {
       startPlayingExploration()
-      playThroughState1()
+      playThroughFractionsState1()
 
       testCoroutineDispatchers.advanceTimeBy(TimeUnit.SECONDS.toMillis(60))
 
@@ -297,7 +306,7 @@ class StateFragmentLocalTest {
   fun testStateFragment_nextState_wait60seconds_canViewOneHint() {
     launchForExploration(FRACTIONS_EXPLORATION_ID_1).use {
       startPlayingExploration()
-      playThroughState1()
+      playThroughFractionsState1()
 
       testCoroutineDispatchers.advanceTimeBy(TimeUnit.SECONDS.toMillis(60))
       openHintsAndSolutionsDialog()
@@ -310,7 +319,7 @@ class StateFragmentLocalTest {
   fun testStateFragment_nextState_wait120seconds_canViewOneHint() {
     launchForExploration(FRACTIONS_EXPLORATION_ID_1).use {
       startPlayingExploration()
-      playThroughState1()
+      playThroughFractionsState1()
 
       testCoroutineDispatchers.advanceTimeBy(TimeUnit.SECONDS.toMillis(120))
       openHintsAndSolutionsDialog()
@@ -324,7 +333,7 @@ class StateFragmentLocalTest {
   fun testStateFragment_portrait_submitCorrectAnswer_correctTextBannerIsDisplayed() {
     launchForExploration(FRACTIONS_EXPLORATION_ID_1).use {
       startPlayingExploration()
-      playThroughState1()
+      playThroughFractionsState1()
 
       onView(withId(R.id.congratulations_text_view))
         .check(matches(isCompletelyDisplayed()))
@@ -336,7 +345,7 @@ class StateFragmentLocalTest {
   fun testStateFragment_landscape_submitCorrectAnswer_correctTextBannerIsDisplayed() {
     launchForExploration(FRACTIONS_EXPLORATION_ID_1).use {
       startPlayingExploration()
-      playThroughState1()
+      playThroughFractionsState1()
 
       onView(withId(R.id.congratulations_text_view))
         .check(matches(isCompletelyDisplayed()))
@@ -348,7 +357,7 @@ class StateFragmentLocalTest {
   fun testStateFragment_portrait_submitCorrectAnswer_confettiIsActive() {
     launchForExploration(FRACTIONS_EXPLORATION_ID_1).use {
       startPlayingExploration()
-      playThroughState1()
+      playThroughFractionsState1()
 
       onView(withId(R.id.congratulations_text_confetti_view)).check(matches(hasActiveConfetti()))
     }
@@ -359,7 +368,7 @@ class StateFragmentLocalTest {
   fun testStateFragment_landscape_submitCorrectAnswer_confettiIsActive() {
     launchForExploration(FRACTIONS_EXPLORATION_ID_1).use {
       startPlayingExploration()
-      playThroughState1()
+      playThroughFractionsState1()
 
       onView(withId(R.id.congratulations_text_confetti_view)).check(matches(hasActiveConfetti()))
     }
@@ -369,10 +378,10 @@ class StateFragmentLocalTest {
   fun testStateFragment_nextState_wait60seconds_submitTwoWrongAnswers_canViewOneHint() {
     launchForExploration(FRACTIONS_EXPLORATION_ID_1).use {
       startPlayingExploration()
-      playThroughState1()
+      playThroughFractionsState1()
 
       testCoroutineDispatchers.advanceTimeBy(TimeUnit.SECONDS.toMillis(60))
-      submitTwoWrongAnswers()
+      submitTwoWrongAnswersForFractionsState2()
       openHintsAndSolutionsDialog()
 
       onView(withText("Hint 1")).inRoot(isDialog()).check(matches(isDisplayed()))
@@ -383,9 +392,9 @@ class StateFragmentLocalTest {
   fun testStateFragment_submitTwoWrongAnswers_checkPreviousHeaderVisible() {
     launchForExploration(FRACTIONS_EXPLORATION_ID_1).use {
       startPlayingExploration()
-      playThroughState1()
+      playThroughFractionsState1()
 
-      submitTwoWrongAnswers()
+      submitTwoWrongAnswersForFractionsState2()
       onView(withId(R.id.state_recycler_view)).perform(scrollToViewType(PREVIOUS_RESPONSES_HEADER))
       testCoroutineDispatchers.runCurrent()
 
@@ -397,9 +406,9 @@ class StateFragmentLocalTest {
   fun testStateFragment_submitTwoWrongAnswers_checkPreviousHeaderCollapsed() {
     launchForExploration(FRACTIONS_EXPLORATION_ID_1).use {
       startPlayingExploration()
-      playThroughState1()
+      playThroughFractionsState1()
 
-      submitTwoWrongAnswers()
+      submitTwoWrongAnswersForFractionsState2()
       onView(withId(R.id.state_recycler_view)).perform(scrollToViewType(PREVIOUS_RESPONSES_HEADER))
       testCoroutineDispatchers.runCurrent()
 
@@ -417,9 +426,9 @@ class StateFragmentLocalTest {
   fun testStateFragment_submitTwoWrongAnswers_expandResponse_checkPreviousHeaderExpanded() {
     launchForExploration(FRACTIONS_EXPLORATION_ID_1).use {
       startPlayingExploration()
-      playThroughState1()
+      playThroughFractionsState1()
 
-      submitTwoWrongAnswers()
+      submitTwoWrongAnswersForFractionsState2()
 
       onView(withId(R.id.state_recycler_view)).perform(scrollToViewType(PREVIOUS_RESPONSES_HEADER))
       testCoroutineDispatchers.runCurrent()
@@ -438,9 +447,9 @@ class StateFragmentLocalTest {
   fun testStateFragment_expandCollapseResponse_checkPreviousHeaderCollapsed() {
     launchForExploration(FRACTIONS_EXPLORATION_ID_1).use {
       startPlayingExploration()
-      playThroughState1()
+      playThroughFractionsState1()
 
-      submitTwoWrongAnswers()
+      submitTwoWrongAnswersForFractionsState2()
 
       onView(withId(R.id.state_recycler_view)).perform(scrollToViewType(PREVIOUS_RESPONSES_HEADER))
       testCoroutineDispatchers.runCurrent()
@@ -475,9 +484,9 @@ class StateFragmentLocalTest {
   fun testStateFragment_nextState_submitInitialWrongAnswer_noHintAvailable() {
     launchForExploration(FRACTIONS_EXPLORATION_ID_1).use {
       startPlayingExploration()
-      playThroughState1()
+      playThroughFractionsState1()
 
-      submitWrongAnswerToState2()
+      submitWrongAnswerToFractionsState2()
 
       // Submitting one wrong answer isn't sufficient to show a hint.
       onView(withId(R.id.hint_bulb)).check(matches(not(isDisplayed())))
@@ -488,9 +497,9 @@ class StateFragmentLocalTest {
   fun testStateFragment_nextState_submitInitialWrongAnswer_wait10seconds_noHintAvailable() {
     launchForExploration(FRACTIONS_EXPLORATION_ID_1).use {
       startPlayingExploration()
-      playThroughState1()
+      playThroughFractionsState1()
 
-      submitWrongAnswerToState2()
+      submitWrongAnswerToFractionsState2()
       testCoroutineDispatchers.advanceTimeBy(TimeUnit.SECONDS.toMillis(10))
 
       // Submitting one wrong answer isn't sufficient to show a hint.
@@ -502,9 +511,9 @@ class StateFragmentLocalTest {
   fun testStateFragment_nextState_submitInitialWrongAnswer_wait30seconds_noHintAvailable() {
     launchForExploration(FRACTIONS_EXPLORATION_ID_1).use {
       startPlayingExploration()
-      playThroughState1()
+      playThroughFractionsState1()
 
-      submitWrongAnswerToState2()
+      submitWrongAnswerToFractionsState2()
       testCoroutineDispatchers.advanceTimeBy(TimeUnit.SECONDS.toMillis(30))
 
       // Submitting one wrong answer isn't sufficient to show a hint.
@@ -516,9 +525,9 @@ class StateFragmentLocalTest {
   fun testStateFragment_nextState_submitTwoWrongAnswers_hintAvailable() {
     launchForExploration(FRACTIONS_EXPLORATION_ID_1).use {
       startPlayingExploration()
-      playThroughState1()
+      playThroughFractionsState1()
 
-      submitTwoWrongAnswers()
+      submitTwoWrongAnswersForFractionsState2()
 
       // Submitting two wrong answers should make the hint immediately available.
       onView(withId(R.id.hint_bulb)).check(matches(isDisplayed()))
@@ -529,8 +538,8 @@ class StateFragmentLocalTest {
   fun testStateFragment_submitTwoWrongAnswers_hintAvailable_prevState_hintNotAvailable() {
     launchForExploration(FRACTIONS_EXPLORATION_ID_1).use {
       startPlayingExploration()
-      playThroughState1()
-      submitTwoWrongAnswers()
+      playThroughFractionsState1()
+      submitTwoWrongAnswersForFractionsState2()
       onView(withId(R.id.hint_bulb)).check(matches(isDisplayed()))
       // The previous navigation button is next to a submit answer button in this state.
       onView(withId(R.id.state_recycler_view)).perform(scrollToViewType(SUBMIT_ANSWER_BUTTON))
@@ -545,8 +554,8 @@ class StateFragmentLocalTest {
   fun testStateFragment_submitTwoWrongAnswers_prevState_currentState_checkDotIconVisible() {
     launchForExploration(FRACTIONS_EXPLORATION_ID_1).use {
       startPlayingExploration()
-      playThroughState1()
-      submitTwoWrongAnswers()
+      playThroughFractionsState1()
+      submitTwoWrongAnswersForFractionsState2()
       onView(withId(R.id.dot_hint)).check(matches(isDisplayed()))
       moveToPreviousAndBackToCurrentStateWithSubmitButton()
       onView(withId(R.id.dot_hint)).check(matches(isDisplayed()))
@@ -557,8 +566,8 @@ class StateFragmentLocalTest {
   fun testStateFragment_oneUnrevealedHint_prevState_currentState_checkOneUnrevealedHintVisible() {
     launchForExploration(FRACTIONS_EXPLORATION_ID_1).use {
       startPlayingExploration()
-      playThroughState1()
-      submitTwoWrongAnswers()
+      playThroughFractionsState1()
+      submitTwoWrongAnswersForFractionsState2()
 
       openHintsAndSolutionsDialog()
       onView(withText("Hint 1")).inRoot(isDialog()).check(matches(isDisplayed()))
@@ -577,9 +586,9 @@ class StateFragmentLocalTest {
   fun testStateFragment_revealFirstHint_prevState_currentState_checkFirstHintRevealed() {
     launchForExploration(FRACTIONS_EXPLORATION_ID_1).use {
       startPlayingExploration()
-      playThroughState1()
+      playThroughFractionsState1()
 
-      produceAndViewFirstHint()
+      produceAndViewFirstHintForFractionState2()
       moveToPreviousAndBackToCurrentStateWithSubmitButton()
       openHintsAndSolutionsDialog()
       onView(withId(R.id.hints_and_solution_recycler_view))
@@ -607,9 +616,9 @@ class StateFragmentLocalTest {
   fun testStateFragment_nextState_submitTwoWrongAnswersAndWait_canViewOneHint() {
     launchForExploration(FRACTIONS_EXPLORATION_ID_1).use {
       startPlayingExploration()
-      playThroughState1()
+      playThroughFractionsState1()
 
-      submitTwoWrongAnswers()
+      submitTwoWrongAnswersForFractionsState2()
       openHintsAndSolutionsDialog()
 
       onView(withText("Hint 1")).inRoot(isDialog()).check(matches(isDisplayed()))
@@ -620,9 +629,9 @@ class StateFragmentLocalTest {
   fun testStateFragment_nextState_submitThreeWrongAnswers_canViewOneHint() {
     launchForExploration(FRACTIONS_EXPLORATION_ID_1).use {
       startPlayingExploration()
-      playThroughState1()
+      playThroughFractionsState1()
 
-      submitThreeWrongAnswersAndWait()
+      submitThreeWrongAnswersForFractionsState2AndWait()
       openHintsAndSolutionsDialog()
 
       onView(withText("Hint 1")).inRoot(isDialog()).check(matches(isDisplayed()))
@@ -634,8 +643,8 @@ class StateFragmentLocalTest {
   fun testStateFragment_nextState_viewHint_newHintIsNoLongerAvailable() {
     launchForExploration(FRACTIONS_EXPLORATION_ID_1).use {
       startPlayingExploration()
-      playThroughState1()
-      submitTwoWrongAnswersAndWait()
+      playThroughFractionsState1()
+      submitTwoWrongAnswersForFractionsState2AndWait()
       openHintsAndSolutionsDialog()
 
       pressRevealHintButton(hintPosition = 0)
@@ -650,8 +659,8 @@ class StateFragmentLocalTest {
   fun testStateFragment_nextState_viewHint_wait10seconds_noNewHintIsAvailable() {
     launchForExploration(FRACTIONS_EXPLORATION_ID_1).use {
       startPlayingExploration()
-      playThroughState1()
-      produceAndViewFirstHint()
+      playThroughFractionsState1()
+      produceAndViewFirstHintForFractionState2()
 
       testCoroutineDispatchers.advanceTimeBy(TimeUnit.SECONDS.toMillis(10))
 
@@ -663,8 +672,8 @@ class StateFragmentLocalTest {
   fun testStateFragment_nextState_viewHint_wait30seconds_newHintIsAvailable() {
     launchForExploration(FRACTIONS_EXPLORATION_ID_1).use {
       startPlayingExploration()
-      playThroughState1()
-      produceAndViewFirstHint()
+      playThroughFractionsState1()
+      produceAndViewFirstHintForFractionState2()
 
       testCoroutineDispatchers.advanceTimeBy(TimeUnit.SECONDS.toMillis(30))
 
@@ -677,8 +686,8 @@ class StateFragmentLocalTest {
   fun testStateFragment_nextState_viewHint_doNotWait_canViewTwoHints() {
     launchForExploration(FRACTIONS_EXPLORATION_ID_1).use {
       startPlayingExploration()
-      playThroughState1()
-      produceAndViewFirstHint()
+      playThroughFractionsState1()
+      produceAndViewFirstHintForFractionState2()
 
       openHintsAndSolutionsDialog()
       onView(withText("Hint 1")).inRoot(isDialog()).check(matches(isDisplayed()))
@@ -692,8 +701,8 @@ class StateFragmentLocalTest {
   fun testStateFragment_nextState_viewHint_wait30seconds_canViewTwoHints() {
     launchForExploration(FRACTIONS_EXPLORATION_ID_1).use {
       startPlayingExploration()
-      playThroughState1()
-      produceAndViewFirstHint()
+      playThroughFractionsState1()
+      produceAndViewFirstHintForFractionState2()
 
       testCoroutineDispatchers.advanceTimeBy(TimeUnit.SECONDS.toMillis(30))
       openHintsAndSolutionsDialog()
@@ -708,8 +717,8 @@ class StateFragmentLocalTest {
   fun testStateFragment_nextState_viewHint_wait60seconds_canViewTwoHints() {
     launchForExploration(FRACTIONS_EXPLORATION_ID_1).use {
       startPlayingExploration()
-      playThroughState1()
-      produceAndViewFirstHint()
+      playThroughFractionsState1()
+      produceAndViewFirstHintForFractionState2()
 
       testCoroutineDispatchers.advanceTimeBy(TimeUnit.SECONDS.toMillis(60))
       openHintsAndSolutionsDialog()
@@ -724,11 +733,11 @@ class StateFragmentLocalTest {
   fun testStateFragment_nextState_viewHint_wait60seconds_submitWrongAnswer_canViewTwoHints() {
     launchForExploration(FRACTIONS_EXPLORATION_ID_1).use {
       startPlayingExploration()
-      playThroughState1()
-      produceAndViewFirstHint()
+      playThroughFractionsState1()
+      produceAndViewFirstHintForFractionState2()
 
       testCoroutineDispatchers.advanceTimeBy(TimeUnit.SECONDS.toMillis(60))
-      submitWrongAnswerToState2()
+      submitWrongAnswerToFractionsState2()
       openHintsAndSolutionsDialog()
 
       // After 60 seconds and one wrong answer submission, only two hints should be available.
@@ -741,10 +750,10 @@ class StateFragmentLocalTest {
   fun testStateFragment_nextState_viewHint_submitWrongAnswer_noNewHintIsAvailable() {
     launchForExploration(FRACTIONS_EXPLORATION_ID_1).use {
       startPlayingExploration()
-      playThroughState1()
-      produceAndViewFirstHint()
+      playThroughFractionsState1()
+      produceAndViewFirstHintForFractionState2()
 
-      submitWrongAnswerToState2()
+      submitWrongAnswerToFractionsState2()
 
       // Submitting a single wrong answer after the previous hint won't immediately show another.
       onView(withId(R.id.dot_hint)).check(matches(not(isDisplayed())))
@@ -755,10 +764,10 @@ class StateFragmentLocalTest {
   fun testStateFragment_nextState_viewHint_submitWrongAnswer_wait10seconds_newHintIsAvailable() {
     launchForExploration(FRACTIONS_EXPLORATION_ID_1).use {
       startPlayingExploration()
-      playThroughState1()
-      produceAndViewFirstHint()
+      playThroughFractionsState1()
+      produceAndViewFirstHintForFractionState2()
 
-      submitWrongAnswerToState2()
+      submitWrongAnswerToFractionsState2()
       testCoroutineDispatchers.advanceTimeBy(TimeUnit.SECONDS.toMillis(10))
 
       // Waiting 10 seconds after submitting a wrong answer should allow another hint to be shown.
@@ -770,10 +779,10 @@ class StateFragmentLocalTest {
   fun testStateFragment_nextState_viewHint_submitWrongAnswer_wait10seconds_canViewTwoHints() {
     launchForExploration(FRACTIONS_EXPLORATION_ID_1).use {
       startPlayingExploration()
-      playThroughState1()
-      produceAndViewFirstHint()
+      playThroughFractionsState1()
+      produceAndViewFirstHintForFractionState2()
 
-      submitWrongAnswerToState2()
+      submitWrongAnswerToFractionsState2()
       testCoroutineDispatchers.advanceTimeBy(TimeUnit.SECONDS.toMillis(10))
       openHintsAndSolutionsDialog()
 
@@ -786,10 +795,10 @@ class StateFragmentLocalTest {
   fun testStateFragment_nextState_viewHint_submitWrongAnswer_wait30seconds_canViewTwoHints() {
     launchForExploration(FRACTIONS_EXPLORATION_ID_1).use {
       startPlayingExploration()
-      playThroughState1()
-      produceAndViewFirstHint()
+      playThroughFractionsState1()
+      produceAndViewFirstHintForFractionState2()
 
-      submitWrongAnswerToState2()
+      submitWrongAnswerToFractionsState2()
       testCoroutineDispatchers.advanceTimeBy(TimeUnit.SECONDS.toMillis(30))
       openHintsAndSolutionsDialog()
 
@@ -803,8 +812,8 @@ class StateFragmentLocalTest {
   fun testStateFragment_nextState_viewFirstHint_configChange_secondHintIsNotAvailableImmediately() {
     launchForExploration(FRACTIONS_EXPLORATION_ID_1).use {
       startPlayingExploration()
-      playThroughState1()
-      produceAndViewFirstHint()
+      playThroughFractionsState1()
+      produceAndViewFirstHintForFractionState2()
 
       onView(isRoot()).perform(orientationLandscape())
       testCoroutineDispatchers.runCurrent()
@@ -816,8 +825,8 @@ class StateFragmentLocalTest {
   fun testStateFragment_nextState_viewFirstHint_configChange_wait30Seconds_secondHintIsAvailable() {
     launchForExploration(FRACTIONS_EXPLORATION_ID_1).use {
       startPlayingExploration()
-      playThroughState1()
-      produceAndViewFirstHint()
+      playThroughFractionsState1()
+      produceAndViewFirstHintForFractionState2()
 
       onView(isRoot()).perform(orientationLandscape())
       testCoroutineDispatchers.runCurrent()
@@ -832,7 +841,7 @@ class StateFragmentLocalTest {
   fun testStateFragment_nextState_newHintAvailable_configChange_newHintIsAvailable() {
     launchForExploration(FRACTIONS_EXPLORATION_ID_1).use {
       startPlayingExploration()
-      playThroughState1()
+      playThroughFractionsState1()
       testCoroutineDispatchers.advanceTimeBy(TimeUnit.SECONDS.toMillis(60))
       onView(withId(R.id.dot_hint)).check(matches(isDisplayed()))
       onView(isRoot()).perform(orientationLandscape())
@@ -845,8 +854,8 @@ class StateFragmentLocalTest {
   fun testStateFragment_nextState_viewFirstHint_prevState_wait30seconds_newHintIsNotAvailable() {
     launchForExploration(FRACTIONS_EXPLORATION_ID_1).use {
       startPlayingExploration()
-      playThroughState1()
-      produceAndViewFirstHint()
+      playThroughFractionsState1()
+      produceAndViewFirstHintForFractionState2()
       clickPreviousStateNavigationButton()
       testCoroutineDispatchers.advanceTimeBy(TimeUnit.SECONDS.toMillis(30))
       onView(withId(R.id.dot_hint)).check(matches(not(isDisplayed())))
@@ -857,8 +866,8 @@ class StateFragmentLocalTest {
   fun testStateFragment_nextState_viewFourHints_wait10seconds_noNewHintIsAvailable() {
     launchForExploration(FRACTIONS_EXPLORATION_ID_1).use {
       startPlayingExploration()
-      playThroughState1()
-      produceAndViewFourHints()
+      playThroughFractionsState1()
+      produceAndViewFourHintsInFractionState2()
 
       testCoroutineDispatchers.advanceTimeBy(TimeUnit.SECONDS.toMillis(10))
 
@@ -870,8 +879,8 @@ class StateFragmentLocalTest {
   fun testStateFragment_nextState_viewFourHints_wait30seconds_newHintIsAvailable() {
     launchForExploration(FRACTIONS_EXPLORATION_ID_1).use {
       startPlayingExploration()
-      playThroughState1()
-      produceAndViewFourHints()
+      playThroughFractionsState1()
+      produceAndViewFourHintsInFractionState2()
 
       testCoroutineDispatchers.advanceTimeBy(TimeUnit.SECONDS.toMillis(30))
 
@@ -884,8 +893,8 @@ class StateFragmentLocalTest {
   fun testStateFragment_nextState_viewFourHints_wait30seconds_canViewSolution() {
     launchForExploration(FRACTIONS_EXPLORATION_ID_1).use {
       startPlayingExploration()
-      playThroughState1()
-      produceAndViewFourHints()
+      playThroughFractionsState1()
+      produceAndViewFourHintsInFractionState2()
 
       testCoroutineDispatchers.advanceTimeBy(TimeUnit.SECONDS.toMillis(30))
       openHintsAndSolutionsDialog()
@@ -907,10 +916,10 @@ class StateFragmentLocalTest {
   fun testStateFragment_nextState_viewFourHints_submitWrongAnswer_noNewHintIsAvailable() {
     launchForExploration(FRACTIONS_EXPLORATION_ID_1).use {
       startPlayingExploration()
-      playThroughState1()
-      produceAndViewFourHints()
+      playThroughFractionsState1()
+      produceAndViewFourHintsInFractionState2()
 
-      submitWrongAnswerToState2()
+      submitWrongAnswerToFractionsState2()
 
       // Submitting a wrong answer will not immediately reveal the solution.
       onView(withId(R.id.dot_hint)).check(matches(not(isDisplayed())))
@@ -921,10 +930,10 @@ class StateFragmentLocalTest {
   fun testStateFragment_nextState_viewFourHints_submitWrongAnswer_wait10s_newHintIsAvailable() {
     launchForExploration(FRACTIONS_EXPLORATION_ID_1).use {
       startPlayingExploration()
-      playThroughState1()
-      produceAndViewFourHints()
+      playThroughFractionsState1()
+      produceAndViewFourHintsInFractionState2()
 
-      submitWrongAnswerToState2()
+      submitWrongAnswerToFractionsState2()
       testCoroutineDispatchers.advanceTimeBy(TimeUnit.SECONDS.toMillis(10))
 
       // Submitting a wrong answer and waiting will reveal the solution.
@@ -936,10 +945,10 @@ class StateFragmentLocalTest {
   fun testStateFragment_nextState_viewFourHints_submitWrongAnswer_wait10s_canViewSolution() {
     launchForExploration(FRACTIONS_EXPLORATION_ID_1).use {
       startPlayingExploration()
-      playThroughState1()
-      produceAndViewFourHints()
+      playThroughFractionsState1()
+      produceAndViewFourHintsInFractionState2()
 
-      submitWrongAnswerToState2()
+      submitWrongAnswerToFractionsState2()
       testCoroutineDispatchers.advanceTimeBy(TimeUnit.SECONDS.toMillis(10))
       openHintsAndSolutionsDialog()
 
@@ -960,10 +969,10 @@ class StateFragmentLocalTest {
   fun testStateFragment_nextState_viewSolution_clickRevealSolutionButton_showsDialog() {
     launchForExploration(FRACTIONS_EXPLORATION_ID_1).use {
       startPlayingExploration()
-      playThroughState1()
-      produceAndViewFourHints()
+      playThroughFractionsState1()
+      produceAndViewFourHintsInFractionState2()
 
-      submitWrongAnswerToState2()
+      submitWrongAnswerToFractionsState2()
       testCoroutineDispatchers.advanceTimeBy(TimeUnit.SECONDS.toMillis(10))
       openHintsAndSolutionsDialog()
 
@@ -989,10 +998,10 @@ class StateFragmentLocalTest {
   fun testStateFragment_nextState_viewRevealSolutionDialog_clickReveal_solutionIsRevealed() {
     launchForExploration(FRACTIONS_EXPLORATION_ID_1).use { scenario ->
       startPlayingExploration()
-      playThroughState1()
-      produceAndViewFourHints()
+      playThroughFractionsState1()
+      produceAndViewFourHintsInFractionState2()
 
-      submitWrongAnswerToState2()
+      submitWrongAnswerToFractionsState2()
       testCoroutineDispatchers.advanceTimeBy(TimeUnit.SECONDS.toMillis(10))
 
       openHintsAndSolutionsDialog()
@@ -1009,10 +1018,10 @@ class StateFragmentLocalTest {
   fun testStateFragment_nextState_viewRevealSolutionDialog_clickReveal_cannotViewRevealSolution() {
     launchForExploration(FRACTIONS_EXPLORATION_ID_1).use { scenario ->
       startPlayingExploration()
-      playThroughState1()
-      produceAndViewFourHints()
+      playThroughFractionsState1()
+      produceAndViewFourHintsInFractionState2()
 
-      submitWrongAnswerToState2()
+      submitWrongAnswerToFractionsState2()
       testCoroutineDispatchers.advanceTimeBy(TimeUnit.SECONDS.toMillis(10))
 
       openHintsAndSolutionsDialog()
@@ -1029,10 +1038,10 @@ class StateFragmentLocalTest {
   fun testStateFragment_nextState_viewRevealSolutionDialog_clickCancel_solutionIsNotRevealed() {
     launchForExploration(FRACTIONS_EXPLORATION_ID_1).use { scenario ->
       startPlayingExploration()
-      playThroughState1()
-      produceAndViewFourHints()
+      playThroughFractionsState1()
+      produceAndViewFourHintsInFractionState2()
 
-      submitWrongAnswerToState2()
+      submitWrongAnswerToFractionsState2()
       testCoroutineDispatchers.advanceTimeBy(TimeUnit.SECONDS.toMillis(10))
 
       openHintsAndSolutionsDialog()
@@ -1049,10 +1058,10 @@ class StateFragmentLocalTest {
   fun testStateFragment_nextState_viewRevealSolutionDialog_clickCancel_canViewRevealSolution() {
     launchForExploration(FRACTIONS_EXPLORATION_ID_1).use { scenario ->
       startPlayingExploration()
-      playThroughState1()
-      produceAndViewFourHints()
+      playThroughFractionsState1()
+      produceAndViewFourHintsInFractionState2()
 
-      submitWrongAnswerToState2()
+      submitWrongAnswerToFractionsState2()
       testCoroutineDispatchers.advanceTimeBy(TimeUnit.SECONDS.toMillis(10))
 
       openHintsAndSolutionsDialog()
@@ -1069,10 +1078,10 @@ class StateFragmentLocalTest {
   fun testStateFragment_nextState_viewSolution_noNewHintIsAvailable() {
     launchForExploration(FRACTIONS_EXPLORATION_ID_1).use { scenario ->
       startPlayingExploration()
-      playThroughState1()
-      produceAndViewFourHints()
+      playThroughFractionsState1()
+      produceAndViewFourHintsInFractionState2()
 
-      produceAndViewSolution(scenario, revealedHintCount = 4)
+      produceAndViewSolutionInFractionsState2(scenario, revealedHintCount = 4)
 
       // No hint should be indicated as available after revealing the solution.
       onView(withId(R.id.dot_hint)).check(matches(not(isDisplayed())))
@@ -1083,9 +1092,9 @@ class StateFragmentLocalTest {
   fun testStateFragment_nextState_viewSolution_wait30seconds_noNewHintIsAvailable() {
     launchForExploration(FRACTIONS_EXPLORATION_ID_1).use { scenario ->
       startPlayingExploration()
-      playThroughState1()
-      produceAndViewFourHints()
-      produceAndViewSolution(scenario, revealedHintCount = 4)
+      playThroughFractionsState1()
+      produceAndViewFourHintsInFractionState2()
+      produceAndViewSolutionInFractionsState2(scenario, revealedHintCount = 4)
 
       testCoroutineDispatchers.advanceTimeBy(TimeUnit.SECONDS.toMillis(30))
 
@@ -1098,11 +1107,11 @@ class StateFragmentLocalTest {
   fun testStateFragment_nextState_viewSolution_submitWrongAnswer_wait10s_noNewHintIsAvailable() {
     launchForExploration(FRACTIONS_EXPLORATION_ID_1).use { scenario ->
       startPlayingExploration()
-      playThroughState1()
-      produceAndViewFourHints()
-      produceAndViewSolution(scenario, revealedHintCount = 4)
+      playThroughFractionsState1()
+      produceAndViewFourHintsInFractionState2()
+      produceAndViewSolutionInFractionsState2(scenario, revealedHintCount = 4)
 
-      submitWrongAnswerToState2()
+      submitWrongAnswerToFractionsState2()
       testCoroutineDispatchers.advanceTimeBy(TimeUnit.SECONDS.toMillis(10))
 
       // Submitting a wrong answer should not change anything since the solution's been revealed.
@@ -1126,10 +1135,10 @@ class StateFragmentLocalTest {
   fun testStateFragment_stateWithoutSolution_viewAllHints_wrongAnswerAndWait_noHintIsAvailable() {
     launchForExploration(FRACTIONS_EXPLORATION_ID_1).use {
       startPlayingExploration()
-      playUpToFinalTestSecondTry()
-      produceAndViewThreeHintsInState13()
+      playUpToFractionsFinalTestSecondTry()
+      produceAndViewThreeHintsInFractionsState13()
 
-      submitWrongAnswerToState13()
+      submitWrongAnswerToFractionsState13()
       testCoroutineDispatchers.advanceTimeBy(TimeUnit.SECONDS.toMillis(10))
 
       // No hint indicator should be shown since there is no solution for this state.
@@ -1137,6 +1146,57 @@ class StateFragmentLocalTest {
     }
   }
 
+  // TODO(#1050): Add a test for verifying that the solution is correct for non-text & non-fraction
+  //  interactions.
+
+  @Test
+  fun testStateFragment_stateWithNumericSolution_revealHint_reopenDialog_onlyOneHintShown() {
+    launchForExploration(TEST_EXPLORATION_ID_2).use {
+      startPlayingExploration()
+      playThroughTestState1()
+      playThroughTestState2()
+      playThroughTestState3()
+      playThroughTestState4()
+      playThroughTestState5()
+      // Trigger the first hint to show (via two incorrect answers), then reveal  it.
+      produceAndViewNextHint(hintPosition = 0) {
+        submitNumericInput(text = "1")
+        submitNumericInput(text = "1")
+      }
+
+      // Reopen the dialog after showing the hint.
+      openHintsAndSolutionsDialog()
+
+      // Verify that the first hint is available, but not the solution.
+      onView(withText("Hint 1")).inRoot(isDialog()).check(matches(isDisplayed()))
+      onView(withText("Solution")).inRoot(isDialog()).check(doesNotExist())
+    }
+  }
+
+  @Test
+  fun testStateFragment_stateWithNumericSolution_revealHint_triggerSolution_hintBulbShown() {
+    launchForExploration(TEST_EXPLORATION_ID_2).use {
+      startPlayingExploration()
+      playThroughTestState1()
+      playThroughTestState2()
+      playThroughTestState3()
+      playThroughTestState4()
+      playThroughTestState5()
+      // Trigger the first hint to show (via two incorrect answers), then reveal  it.
+      produceAndViewNextHint(hintPosition = 0) {
+        submitNumericInput(text = "1")
+        submitNumericInput(text = "1")
+      }
+
+      // Trigger the solution to show by submitting another incorrect answer & waiting.
+      submitNumericInput(text = "1")
+      testCoroutineDispatchers.advanceTimeBy(TimeUnit.SECONDS.toMillis(10))
+
+      // The new hint indicator should be shown since a solution is now available.
+      onView(withId(R.id.dot_hint)).check(matches(isDisplayed()))
+    }
+  }
+
   @Test
   @DefineAppLanguageLocaleContext(
     oppiaLanguageEnumId = ENGLISH_VALUE,
@@ -1304,7 +1364,7 @@ class StateFragmentLocalTest {
   fun testStateFragment_mobilePortrait_finishExploration_endOfSessionConfettiIsDisplayed() {
     launchForExploration(FRACTIONS_EXPLORATION_ID_1).use {
       startPlayingExploration()
-      playThroughAllStates()
+      playThroughAllFractionsStates()
       clickContinueButton()
 
       onView(withId(R.id.full_screen_confetti_view)).check(matches(hasActiveConfetti()))
@@ -1316,7 +1376,7 @@ class StateFragmentLocalTest {
   fun testStateFragment_mobileLandscape_finishExploration_endOfSessionConfettiIsDisplayed() {
     launchForExploration(FRACTIONS_EXPLORATION_ID_1).use {
       startPlayingExploration()
-      playThroughAllStates()
+      playThroughAllFractionsStates()
       clickContinueButton()
 
       onView(withId(R.id.full_screen_confetti_view)).check(matches(hasActiveConfetti()))
@@ -1330,7 +1390,7 @@ class StateFragmentLocalTest {
   fun testStateFragment_tabletPortrait_finishExploration_endOfSessionConfettiIsDisplayed() {
     launchForExploration(FRACTIONS_EXPLORATION_ID_1).use {
       startPlayingExploration()
-      playThroughAllStates()
+      playThroughAllFractionsStates()
       clickContinueButton()
 
       onView(withId(R.id.full_screen_confetti_view)).check(matches(hasActiveConfetti()))
@@ -1344,7 +1404,7 @@ class StateFragmentLocalTest {
   fun testStateFragment_tabletLandscape_finishExploration_endOfSessionConfettiIsDisplayed() {
     launchForExploration(FRACTIONS_EXPLORATION_ID_1).use {
       startPlayingExploration()
-      playThroughAllStates()
+      playThroughAllFractionsStates()
       clickContinueButton()
 
       onView(withId(R.id.full_screen_confetti_view)).check(matches(hasActiveConfetti()))
@@ -1356,7 +1416,7 @@ class StateFragmentLocalTest {
   fun testStateFragment_finishExploration_changePortToLand_endOfSessionConfettiIsDisplayedAgain() {
     launchForExploration(FRACTIONS_EXPLORATION_ID_1).use {
       startPlayingExploration()
-      playThroughAllStates()
+      playThroughAllFractionsStates()
       clickContinueButton()
       onView(withId(R.id.full_screen_confetti_view)).check(
         matches(
@@ -1379,7 +1439,7 @@ class StateFragmentLocalTest {
   fun testStateFragment_finishExploration_changeLandToPort_endOfSessionConfettiIsDisplayedAgain() {
     launchForExploration(FRACTIONS_EXPLORATION_ID_1).use {
       startPlayingExploration()
-      playThroughAllStates()
+      playThroughAllFractionsStates()
       clickContinueButton()
       onView(withId(R.id.full_screen_confetti_view)).check(
         matches(
@@ -1401,7 +1461,7 @@ class StateFragmentLocalTest {
   fun testStateFragment_submitCorrectAnswer_endOfSessionConfettiDoesNotStart() {
     launchForExploration(FRACTIONS_EXPLORATION_ID_1).use {
       startPlayingExploration()
-      playThroughState1()
+      playThroughFractionsState1()
 
       onView(withId(R.id.full_screen_confetti_view)).check(matches(not(hasActiveConfetti())))
     }
@@ -1412,7 +1472,7 @@ class StateFragmentLocalTest {
     launchForExploration(FRACTIONS_EXPLORATION_ID_1).use {
       startPlayingExploration()
       // Play through all questions but do not reach the last screen of the exploration.
-      playThroughAllStates()
+      playThroughAllFractionsStates()
 
       onView(withId(R.id.full_screen_confetti_view)).check(matches(not(hasActiveConfetti())))
     }
@@ -1422,7 +1482,7 @@ class StateFragmentLocalTest {
   fun testStateFragment_reachEndOfExplorationTwice_endOfSessionConfettiIsDisplayedOnce() {
     launchForExploration(FRACTIONS_EXPLORATION_ID_1).use {
       startPlayingExploration()
-      playThroughAllStates()
+      playThroughAllFractionsStates()
       clickContinueButton()
       onView(withId(R.id.full_screen_confetti_view)).check(matches(hasActiveConfetti()))
       onView(withId(R.id.full_screen_confetti_view)).check(
@@ -1477,113 +1537,140 @@ class StateFragmentLocalTest {
     testCoroutineDispatchers.runCurrent()
   }
 
-  private fun playThroughState1() {
+  private fun playThroughFractionsState1() {
     onView(withId(R.id.state_recycler_view)).perform(scrollToViewType(SELECTION_INTERACTION))
     onView(withSubstring("the pieces must be the same size.")).perform(click())
     testCoroutineDispatchers.runCurrent()
     clickContinueNavigationButton()
   }
 
-  private fun playThroughState2() {
+  private fun playThroughFractionsState2() {
     // Correct answer to 'Matthew gets conned'
     submitFractionAnswer(answerText = "3/4")
     clickContinueNavigationButton()
   }
 
-  private fun playThroughState3() {
+  private fun playThroughFractionsState3() {
     // Correct answer to 'Question 1'
     submitFractionAnswer(answerText = "4/9")
     clickContinueNavigationButton()
   }
 
-  private fun playThroughState4() {
+  private fun playThroughFractionsState4() {
     // Correct answer to 'Question 2'
     submitFractionAnswer(answerText = "1/4")
     clickContinueNavigationButton()
   }
 
-  private fun playThroughState5() {
+  private fun playThroughFractionsState5() {
     // Correct answer to 'Question 3'
     submitFractionAnswer(answerText = "1/8")
     clickContinueNavigationButton()
   }
 
-  private fun playThroughState6() {
+  private fun playThroughFractionsState6() {
     // Correct answer to 'Question 4'
     submitFractionAnswer(answerText = "1/2")
     clickContinueNavigationButton()
   }
 
-  private fun playThroughState7() {
+  private fun playThroughFractionsState7() {
     // Correct answer to 'Question 5' which redirects the learner to 'Thinking in fractions Q1'
     submitFractionAnswer(answerText = "2/9")
     clickContinueNavigationButton()
   }
 
-  private fun playThroughState8() {
+  private fun playThroughFractionsState8() {
     // Correct answer to 'Thinking in fractions Q1'
     submitFractionAnswer(answerText = "7/9")
     clickContinueNavigationButton()
   }
 
-  private fun playThroughState9() {
+  private fun playThroughFractionsState9() {
     // Correct answer to 'Thinking in fractions Q2'
     submitFractionAnswer(answerText = "4/9")
     clickContinueNavigationButton()
   }
 
-  private fun playThroughState10() {
+  private fun playThroughFractionsState10() {
     // Correct answer to 'Thinking in fractions Q3'
     submitFractionAnswer(answerText = "5/8")
     clickContinueNavigationButton()
   }
 
-  private fun playThroughState11() {
+  private fun playThroughFractionsState11() {
     // Correct answer to 'Thinking in fractions Q4' which redirects the learner to 'Final Test A'
     submitFractionAnswer(answerText = "3/4")
     clickContinueNavigationButton()
   }
 
-  private fun playThroughState12() {
+  private fun playThroughFractionsState12() {
     // Correct answer to 'Final Test A' redirects learner to 'Happy ending'
     submitFractionAnswer(answerText = "2/4")
     clickContinueNavigationButton()
   }
 
-  private fun playThroughState12WithWrongAnswer() {
+  private fun playThroughFractionsState12WithWrongAnswer() {
     // Incorrect answer to 'Final Test A' redirects the learner to 'Final Test A second try'
     submitFractionAnswer(answerText = "1/9")
     clickContinueNavigationButton()
   }
 
-  private fun playUpToFinalTestSecondTry() {
-    playThroughState1()
-    playThroughState2()
-    playThroughState3()
-    playThroughState4()
-    playThroughState5()
-    playThroughState6()
-    playThroughState7()
-    playThroughState8()
-    playThroughState9()
-    playThroughState10()
-    playThroughState11()
-    playThroughState12WithWrongAnswer()
-  }
-
-  private fun playThroughAllStates() {
-    playThroughState1()
-    playThroughState2()
-    playThroughState3()
-    playThroughState4()
-    playThroughState5()
-    playThroughState6()
-    playThroughState7()
-    playThroughState8()
-    playThroughState9()
-    playThroughState10()
-    playThroughState11()
-    playThroughState12()
+  private fun playUpToFractionsFinalTestSecondTry() {
+    playThroughFractionsState1()
+    playThroughFractionsState2()
+    playThroughFractionsState3()
+    playThroughFractionsState4()
+    playThroughFractionsState5()
+    playThroughFractionsState6()
+    playThroughFractionsState7()
+    playThroughFractionsState8()
+    playThroughFractionsState9()
+    playThroughFractionsState10()
+    playThroughFractionsState11()
+    playThroughFractionsState12WithWrongAnswer()
+  }
+
+  private fun playThroughAllFractionsStates() {
+    playThroughFractionsState1()
+    playThroughFractionsState2()
+    playThroughFractionsState3()
+    playThroughFractionsState4()
+    playThroughFractionsState5()
+    playThroughFractionsState6()
+    playThroughFractionsState7()
+    playThroughFractionsState8()
+    playThroughFractionsState9()
+    playThroughFractionsState10()
+    playThroughFractionsState11()
+    playThroughFractionsState12()
+  }
+
+  private fun playThroughTestState1() {
+    clickContinueButton()
+  }
+
+  private fun playThroughTestState2() {
+    submitFractionAnswer(answerText = "1/2")
+    clickContinueNavigationButton()
+  }
+
+  private fun playThroughTestState3() {
+    selectMultipleChoiceOption(optionPosition = 2, expectedOptionText = "Eagle")
+    clickContinueNavigationButton()
+  }
+
+  private fun playThroughTestState4() {
+    selectMultipleChoiceOption(optionPosition = 0, expectedOptionText = "Green")
+    clickContinueNavigationButton()
+  }
+
+  private fun playThroughTestState5() {
+    selectItemSelectionCheckbox(optionPosition = 0, expectedOptionText = "Red")
+    selectItemSelectionCheckbox(optionPosition = 2, expectedOptionText = "Green")
+    selectItemSelectionCheckbox(optionPosition = 3, expectedOptionText = "Blue")
+    clickSubmitAnswerButton()
+    clickContinueNavigationButton()
   }
 
   private fun clickContinueNavigationButton() {
@@ -1600,6 +1687,12 @@ class StateFragmentLocalTest {
     testCoroutineDispatchers.runCurrent()
   }
 
+  private fun clickSubmitAnswerButton() {
+    onView(withId(R.id.state_recycler_view)).perform(scrollToViewType(SUBMIT_ANSWER_BUTTON))
+    onView(withId(R.id.submit_answer_button)).perform(click())
+    testCoroutineDispatchers.runCurrent()
+  }
+
   private fun clickNextStateNavigationButton() {
     onView(withId(R.id.next_state_navigation_button)).perform(click())
     testCoroutineDispatchers.runCurrent()
@@ -1654,58 +1747,117 @@ class StateFragmentLocalTest {
     testCoroutineDispatchers.runCurrent()
   }
 
-  private fun submitFractionAnswer(answerText: String) {
+  private fun typeFractionAnswer(answerText: String) {
     onView(withId(R.id.state_recycler_view)).perform(scrollToViewType(FRACTION_INPUT_INTERACTION))
-    onView(withId(R.id.fraction_input_interaction_view)).perform(
-      editTextInputAction.appendText(answerText)
+    typeTextIntoInteraction(answerText, interactionViewId = R.id.fraction_input_interaction_view)
+  }
+
+  private fun submitFractionAnswer(answerText: String) {
+    typeFractionAnswer(answerText)
+    clickSubmitAnswerButton()
+  }
+
+  private fun selectMultipleChoiceOption(optionPosition: Int, expectedOptionText: String) {
+    clickSelection(
+      optionPosition,
+      targetClickViewId = R.id.multiple_choice_radio_button,
+      expectedText = expectedOptionText,
+      targetTextViewId = R.id.multiple_choice_content_text_view
+    )
+  }
+
+  private fun selectItemSelectionCheckbox(optionPosition: Int, expectedOptionText: String) {
+    clickSelection(
+      optionPosition,
+      targetClickViewId = R.id.item_selection_checkbox,
+      expectedText = expectedOptionText,
+      targetTextViewId = R.id.item_selection_contents_text_view
     )
+  }
+
+  private fun typeNumericInput(text: String) {
+    onView(withId(R.id.state_recycler_view)).perform(scrollToViewType(NUMERIC_INPUT_INTERACTION))
+    typeTextIntoInteraction(text, interactionViewId = R.id.numeric_input_interaction_view)
+  }
+
+  private fun submitNumericInput(text: String) {
+    typeNumericInput(text)
+    clickSubmitAnswerButton()
+  }
+
+  private fun typeTextIntoInteraction(text: String, interactionViewId: Int) {
+    onView(withId(interactionViewId)).perform(editTextInputAction.appendText(text))
     testCoroutineDispatchers.runCurrent()
+  }
 
-    onView(withId(R.id.state_recycler_view)).perform(scrollToViewType(SUBMIT_ANSWER_BUTTON))
-    onView(withId(R.id.submit_answer_button)).perform(click())
+  private fun clickSelection(
+    optionPosition: Int,
+    targetClickViewId: Int,
+    expectedText: String,
+    targetTextViewId: Int
+  ) {
+    onView(withId(R.id.state_recycler_view)).perform(scrollToViewType(SELECTION_INTERACTION))
+    // First, check that the option matches what's expected by the test.
+    onView(
+      atPositionOnView(
+        recyclerViewId = R.id.selection_interaction_recyclerview,
+        position = optionPosition,
+        targetViewId = targetTextViewId
+      )
+    ).check(matches(withText(containsString(expectedText))))
+    // Then, click on it.
+    onView(
+      atPositionOnView(
+        recyclerViewId = R.id.selection_interaction_recyclerview,
+        position = optionPosition,
+        targetViewId = targetClickViewId
+      )
+    ).perform(click())
     testCoroutineDispatchers.runCurrent()
   }
 
-  private fun submitWrongAnswerToState2() {
+  private fun submitWrongAnswerToFractionsState2() {
     submitFractionAnswer(answerText = "1/2")
   }
 
-  private fun submitWrongAnswerToState2AndWait() {
-    submitWrongAnswerToState2()
+  private fun submitWrongAnswerToFractionsState2AndWait() {
+    submitWrongAnswerToFractionsState2()
     testCoroutineDispatchers.advanceTimeBy(TimeUnit.SECONDS.toMillis(10))
   }
 
-  private fun submitWrongAnswerToState13() {
+  private fun submitWrongAnswerToFractionsState13() {
     submitFractionAnswer(answerText = "1/9")
   }
 
-  private fun submitWrongAnswerToState13AndWait() {
-    submitWrongAnswerToState13()
+  private fun submitWrongAnswerToFractionsState13AndWait() {
+    submitWrongAnswerToFractionsState13()
     testCoroutineDispatchers.advanceTimeBy(TimeUnit.SECONDS.toMillis(10))
   }
 
-  private fun submitTwoWrongAnswers() {
-    submitWrongAnswerToState2()
-    submitWrongAnswerToState2()
+  private fun submitTwoWrongAnswersForFractionsState2() {
+    submitWrongAnswerToFractionsState2()
+    submitWrongAnswerToFractionsState2()
   }
 
-  private fun submitTwoWrongAnswersAndWait() {
-    submitTwoWrongAnswers()
+  private fun submitTwoWrongAnswersForFractionsState2AndWait() {
+    submitTwoWrongAnswersForFractionsState2()
     testCoroutineDispatchers.advanceTimeBy(TimeUnit.SECONDS.toMillis(10))
   }
 
-  private fun submitThreeWrongAnswersAndWait() {
-    submitWrongAnswerToState2()
-    submitWrongAnswerToState2()
-    submitWrongAnswerToState2()
+  private fun submitThreeWrongAnswersForFractionsState2AndWait() {
+    submitWrongAnswerToFractionsState2()
+    submitWrongAnswerToFractionsState2()
+    submitWrongAnswerToFractionsState2()
     testCoroutineDispatchers.advanceTimeBy(TimeUnit.SECONDS.toMillis(10))
   }
 
-  private fun produceAndViewFirstHint() {
+  private fun produceAndViewFirstHintForFractionState2() {
     // Two wrong answers need to be submitted for the first hint to show up, so submit an extra one
     // in advance of the standard show & reveal hint flow.
-    submitWrongAnswerToState2()
-    produceAndViewNextHint(hintPosition = 0, submitAnswer = this::submitWrongAnswerToState2AndWait)
+    submitWrongAnswerToFractionsState2()
+    produceAndViewNextHint(
+      hintPosition = 0, submitAnswer = this::submitWrongAnswerToFractionsState2AndWait
+    )
   }
 
   /**
@@ -1719,27 +1871,39 @@ class StateFragmentLocalTest {
     closeHintsAndSolutionsDialog()
   }
 
-  private fun produceAndViewThreeHintsInState13() {
-    submitWrongAnswerToState13()
-    produceAndViewNextHint(hintPosition = 0, submitAnswer = this::submitWrongAnswerToState13AndWait)
-    produceAndViewNextHint(hintPosition = 1, submitAnswer = this::submitWrongAnswerToState13AndWait)
-    produceAndViewNextHint(hintPosition = 2, submitAnswer = this::submitWrongAnswerToState13AndWait)
+  private fun produceAndViewThreeHintsInFractionsState13() {
+    submitWrongAnswerToFractionsState13()
+    produceAndViewNextHint(
+      hintPosition = 0, submitAnswer = this::submitWrongAnswerToFractionsState13AndWait
+    )
+    produceAndViewNextHint(
+      hintPosition = 1, submitAnswer = this::submitWrongAnswerToFractionsState13AndWait
+    )
+    produceAndViewNextHint(
+      hintPosition = 2, submitAnswer = this::submitWrongAnswerToFractionsState13AndWait
+    )
   }
 
-  private fun produceAndViewFourHints() {
+  private fun produceAndViewFourHintsInFractionState2() {
     // Cause three hints to show, and reveal each of them one at a time (to allow the later hints
     // to be shown).
-    produceAndViewFirstHint()
-    produceAndViewNextHint(hintPosition = 1, submitAnswer = this::submitWrongAnswerToState2AndWait)
-    produceAndViewNextHint(hintPosition = 2, submitAnswer = this::submitWrongAnswerToState2AndWait)
-    produceAndViewNextHint(hintPosition = 3, submitAnswer = this::submitWrongAnswerToState2AndWait)
+    produceAndViewFirstHintForFractionState2()
+    produceAndViewNextHint(
+      hintPosition = 1, submitAnswer = this::submitWrongAnswerToFractionsState2AndWait
+    )
+    produceAndViewNextHint(
+      hintPosition = 2, submitAnswer = this::submitWrongAnswerToFractionsState2AndWait
+    )
+    produceAndViewNextHint(
+      hintPosition = 3, submitAnswer = this::submitWrongAnswerToFractionsState2AndWait
+    )
   }
 
-  private fun produceAndViewSolution(
+  private fun produceAndViewSolutionInFractionsState2(
     activityScenario: ActivityScenario<StateFragmentTestActivity>,
     revealedHintCount: Int
   ) {
-    submitWrongAnswerToState2AndWait()
+    submitWrongAnswerToFractionsState2AndWait()
     openHintsAndSolutionsDialog()
     pressRevealSolutionButton(revealedHintCount)
     clickConfirmRevealSolutionButton(activityScenario)
@@ -1855,19 +2019,40 @@ class StateFragmentLocalTest {
       })
   }
 
+  // TODO(#89): Move this to a common test application component.
+  @Module
+  class TestModule {
+    @Provides
+    @LoadLessonProtosFromAssets
+    fun provideLoadLessonProtosFromAssets(testEnvironmentConfig: TestEnvironmentConfig): Boolean =
+      testEnvironmentConfig.isUsingBazel()
+
+    @Provides
+    @CacheAssetsLocally
+    fun provideCacheAssetsLocally(): Boolean = false
+
+    @Provides
+    @TopicListToCache
+    fun provideTopicListToCache(): List<String> = listOf()
+
+    @Provides
+    @LoadImagesFromAssets
+    fun provideLoadImagesFromAssets(): Boolean = false
+  }
+
   // TODO(#59): Figure out a way to reuse modules instead of needing to re-declare them.
   @Singleton
   @Component(
     modules = [
-      TestDispatcherModule::class, ApplicationModule::class, RobolectricModule::class,
-      PlatformParameterModule::class, PlatformParameterSingletonModule::class,
-      LoggerModule::class, ContinueModule::class, FractionInputModule::class,
-      ItemSelectionInputModule::class, MultipleChoiceInputModule::class,
+      TestModule::class, TestDispatcherModule::class, ApplicationModule::class,
+      RobolectricModule::class, PlatformParameterModule::class,
+      PlatformParameterSingletonModule::class, LoggerModule::class, ContinueModule::class,
+      FractionInputModule::class, ItemSelectionInputModule::class, MultipleChoiceInputModule::class,
       NumberWithUnitsRuleModule::class, NumericInputRuleModule::class, TextInputRuleModule::class,
       DragDropSortInputModule::class, ImageClickInputModule::class, InteractionsModule::class,
       GcsResourceModule::class, GlideImageLoaderModule::class, ImageParsingModule::class,
       HtmlParserEntityTypeModule::class, QuestionModule::class, TestLogReportingModule::class,
-      AccessibilityTestModule::class, LogStorageModule::class, CachingTestModule::class,
+      AccessibilityTestModule::class, LogStorageModule::class,
       PrimeTopicAssetsControllerModule::class, ExpirationMetaDataRetrieverModule::class,
       ViewBindingShimModule::class, RatioInputModule::class, WorkManagerConfigurationModule::class,
       ApplicationStartupListenerModule::class, LogUploadWorkerModule::class,
diff --git a/domain/BUILD.bazel b/domain/BUILD.bazel
index 9faa5f96aac..bcf339683d2 100755
--- a/domain/BUILD.bazel
+++ b/domain/BUILD.bazel
@@ -50,6 +50,7 @@ DOMAIN_ASSETS = generate_assets_list_from_text_protos(
         "test_single_interactive_state_exp_with_one_hint_and_solution",
         "test_single_interactive_state_exp_with_one_hint_and_no_solution",
         "test_single_interactive_state_exp_with_only_solution",
+        "test_single_interactive_state_exp_with_solution_missing_answer",
     ],
     skills_file_names = [
         "skills",
diff --git a/domain/src/main/assets/test_exp_id_2.json b/domain/src/main/assets/test_exp_id_2.json
index dd5637e5cfb..e108d537190 100644
--- a/domain/src/main/assets/test_exp_id_2.json
+++ b/domain/src/main/assets/test_exp_id_2.json
@@ -692,8 +692,20 @@
             "refresher_exploration_id": "",
             "missing_prerequisite_skill_id": ""
           },
-          "hints": [],
-          "solution": null
+          "hints": [{
+            "hint_content": {
+              "content_id": "hint_1",
+              "html": "<p>11 * 11 can be rephrased as 11 * 10, then add 11 at the end.</p>"
+            }
+          }],
+          "solution": {
+            "answer_is_exclusive": false,
+            "correct_answer": "",
+            "explanation": {
+              "content_id": "solution",
+              "html": "<p>11 times 11 is 121.</p>"
+            }
+          }
         },
         "classifier_model_id": "",
         "recorded_voiceovers": {
@@ -702,11 +714,37 @@
             "feedback_3": {},
             "feedback_1": {},
             "content": {},
-            "default_outcome": {}
+            "default_outcome": {},
+            "hint_1": {},
+            "solution": {}
           }
         },
         "written_translations": {
           "translations_mapping": {
+            "hint_1": {
+              "pt": {
+                "data_format": "html",
+                "translation": {"translation" : "<p> 11 * 11 pode ser reformulado como 11 * 10 e, em seguida, adicione 11 no final. </p>"},
+                "needs_update": false
+              },
+              "ar": {
+                "data_format": "html",
+                "translation": {"translation" : "يمكن إعادة صياغة <p> 11 * 11 على أنها 11 * 10، ثم أضف 11 في النهاية. </p>"},
+                "needs_update": false
+              }
+            },
+            "solution": {
+              "pt": {
+                "data_format": "html",
+                "translation": {"translation" : "<p> 11 vezes 11 é 121. </p>"},
+                "needs_update": false
+              },
+              "ar": {
+                "data_format": "html",
+                "translation": {"translation" : "<p> 11 مرات 11 هو 121. </p>"},
+                "needs_update": false
+              }
+            },
             "feedback_2": {
               "pt": {
                 "data_format": "html",
diff --git a/domain/src/main/assets/test_exp_id_2.textproto b/domain/src/main/assets/test_exp_id_2.textproto
index 58cffe4084a..075f3bb457f 100644
--- a/domain/src/main/assets/test_exp_id_2.textproto
+++ b/domain/src/main/assets/test_exp_id_2.textproto
@@ -825,10 +825,54 @@ states {
       value {
       }
     }
+    recorded_voiceovers {
+      key: "hint_1"
+      value {
+      }
+    }
+    recorded_voiceovers {
+      key: "solution"
+      value {
+      }
+    }
     content {
       html: "<p>What is 11 times 11?</p>"
       content_id: "content"
     }
+    written_translations {
+      key: "hint_1"
+      value {
+        translation_mapping {
+          key: "pt"
+          value {
+            html: "<p> 11 * 11 pode ser reformulado como 11 * 10 e, em seguida, adicione 11 no final. </p>"
+          }
+        }
+        translation_mapping {
+          key: "ar"
+          value {
+            html: "\331\212\331\205\331\203\331\206 \330\245\330\271\330\247\330\257\330\251 \330\265\331\212\330\247\330\272\330\251 <p> 11 * 11 \330\271\331\204\331\211 \330\243\331\206\331\207\330\247 11 * 10\330\214 \330\253\331\205 \330\243\330\266\331\201 11 \331\201\331\212 \330\247\331\204\331\206\331\207\330\247\331\212\330\251. </p>"
+          }
+        }
+      }
+    }
+    written_translations {
+      key: "solution"
+      value {
+        translation_mapping {
+          key: "pt"
+          value {
+            html: "<p> 11 vezes 11 \303\251 121. </p>"
+          }
+        }
+        translation_mapping {
+          key: "ar"
+          value {
+            html: "<p> 11 \331\205\330\261\330\247\330\252 11 \331\207\331\210 121. </p>"
+          }
+        }
+      }
+    }
     written_translations {
       key: "feedback_2"
       value {
@@ -970,6 +1014,19 @@ states {
           rule_type: "IsGreaterThan"
         }
       }
+      solution {
+        interaction_id: "NumericInput"
+        explanation {
+          html: "<p>11 times 11 is 121.</p>"
+          content_id: "solution"
+        }
+      }
+      hint {
+        hint_content {
+          html: "<p>11 * 11 can be rephrased as 11 * 10, then add 11 at the end.</p>"
+          content_id: "hint_1"
+        }
+      }
       default_outcome {
         dest_state_name: "NumberInput"
         feedback {
diff --git a/domain/src/main/assets/test_single_interactive_state_exp_with_solution_missing_answer.json b/domain/src/main/assets/test_single_interactive_state_exp_with_solution_missing_answer.json
new file mode 100644
index 00000000000..5ddc99450b0
--- /dev/null
+++ b/domain/src/main/assets/test_single_interactive_state_exp_with_solution_missing_answer.json
@@ -0,0 +1,112 @@
+{
+  "exploration_id": "test_single_interactive_state_exp_with_solution_missing_answer",
+  "version": 1,
+  "exploration": {
+    "init_state_name": "Text",
+    "states": {
+      "Text": {
+        "content": {
+          "content_id": "content",
+          "html": "<p>In which language does Oppia mean 'to learn'?</p>"
+        },
+        "interaction": {
+          "id": "TextInput",
+          "customization_args": {
+            "rows": {
+              "value": 1.0
+            },
+            "placeholder": {
+              "value": {
+                "content_id": "ca_placeholder_0",
+                "unicode_str": "Enter a language"
+              }
+            }
+          },
+          "answer_groups": [{
+            "rule_specs": [{
+              "rule_type": "Equals",
+              "inputs": {
+                "x": {
+                  "contentId": "<unknown>",
+                  "normalizedStrSet": ["finnish"]
+                }
+              }
+            }],
+            "outcome": {
+              "dest": "End",
+              "feedback": {
+                "content_id": "feedback_1",
+                "html": "<p>Correct!</p>"
+              },
+              "labelled_as_correct": false
+            }
+          }],
+          "default_outcome": {
+            "dest": "Text",
+            "feedback": {
+              "content_id": "default_outcome",
+              "html": "<p>Not quite. Try again (or maybe use a search engine).</p>"
+            },
+            "labelled_as_correct": false
+          },
+          "hints": [],
+          "solution": {
+            "answer_is_exclusive": false,
+            "explanation": {
+              "content_id": "solution",
+              "html": "<p>'Oppia' is translated from Finnish.</p>"
+            }
+          }
+        },
+        "recorded_voiceovers": {
+          "voiceovers_mapping": {
+            "feedback_1": {},
+            "content": {},
+            "default_outcome": {},
+            "solution": {}
+          }
+        },
+        "written_translations": {
+          "translations_mapping": {
+            "feedback_1": {},
+            "content": {},
+            "default_outcome": {},
+            "solution": {}
+          }
+        }
+      },
+      "End": {
+        "content": {
+          "content_id": "content",
+          "html": "Congratulations, you have finished!"
+        },
+        "param_changes": [],
+        "interaction": {
+          "id": "EndExploration",
+          "customization_args": {
+            "recommendedExplorationIds": {
+              "value": []
+            }
+          },
+          "answer_groups": [],
+          "default_outcome": null,
+          "hints": [],
+          "solution": null
+        },
+        "recorded_voiceovers": {
+          "voiceovers_mapping": {
+            "content": {}
+          }
+        },
+        "written_translations": {
+          "translations_mapping": {
+            "content": {}
+          }
+        }
+      }
+    },
+    "objective": "Test exploration.",
+    "language_code": "en",
+    "title": "Prototype exploration with only one solution and no hints"
+  }
+}
diff --git a/domain/src/main/assets/test_single_interactive_state_exp_with_solution_missing_answer.textproto b/domain/src/main/assets/test_single_interactive_state_exp_with_solution_missing_answer.textproto
new file mode 100644
index 00000000000..1c3bb7d9a8d
--- /dev/null
+++ b/domain/src/main/assets/test_single_interactive_state_exp_with_solution_missing_answer.textproto
@@ -0,0 +1,140 @@
+id: "test_single_interactive_state_exp_with_solution_missing_answer"
+states {
+  key: "Text"
+  value {
+    name: "Text"
+    recorded_voiceovers {
+      key: "feedback_1"
+      value {
+      }
+    }
+    recorded_voiceovers {
+      key: "content"
+      value {
+      }
+    }
+    recorded_voiceovers {
+      key: "default_outcome"
+      value {
+      }
+    }
+    recorded_voiceovers {
+      key: "solution"
+      value {
+      }
+    }
+    content {
+      html: "<p>In which language does Oppia mean \'to learn\'?</p>"
+      content_id: "content"
+    }
+    written_translations {
+      key: "feedback_1"
+      value {
+      }
+    }
+    written_translations {
+      key: "content"
+      value {
+      }
+    }
+    written_translations {
+      key: "default_outcome"
+      value {
+      }
+    }
+    written_translations {
+      key: "solution"
+      value {
+      }
+    }
+    interaction {
+      id: "TextInput"
+      answer_groups {
+        outcome {
+          dest_state_name: "End"
+          feedback {
+            html: "<p>Correct!</p>"
+            content_id: "feedback_1"
+          }
+        }
+        rule_specs {
+          input {
+            key: "x"
+            value {
+              translatable_set_of_normalized_string {
+                content_id: "<unknown>"
+                normalized_strings: "finnish"
+              }
+            }
+          }
+          rule_type: "Equals"
+        }
+      }
+      solution {
+        interaction_id: "TextInput"
+        explanation {
+          html: "<p>'Oppia' is translated from Finnish.</p>"
+          content_id: "solution"
+        }
+      }
+      default_outcome {
+        dest_state_name: "Text"
+        feedback {
+          html: "<p>Not quite. Try again (or maybe use a search engine).</p>"
+          content_id: "default_outcome"
+        }
+      }
+      customization_args {
+        key: "rows"
+        value {
+          signed_int: 1
+        }
+      }
+      customization_args {
+        key: "placeholder"
+        value {
+          custom_schema_value {
+            subtitled_html {
+              html: "Enter a language"
+              content_id: "ca_placeholder_0"
+            }
+          }
+        }
+      }
+    }
+  }
+}
+states {
+  key: "End"
+  value {
+    name: "End"
+    recorded_voiceovers {
+      key: "content"
+      value {
+      }
+    }
+    content {
+      html: "Congratulations, you have finished!"
+      content_id: "content"
+    }
+    written_translations {
+      key: "content"
+      value {
+      }
+    }
+    interaction {
+      id: "EndExploration"
+      customization_args {
+        key: "recommendedExplorationIds"
+        value {
+          schema_object_list {
+          }
+        }
+      }
+    }
+  }
+}
+init_state_name: "Text"
+objective: "Test exploration."
+title: "Prototype exploration with only one solution and no hints"
+language_code: "en"
diff --git a/domain/src/main/java/org/oppia/android/domain/hintsandsolution/HintHandlerProdImpl.kt b/domain/src/main/java/org/oppia/android/domain/hintsandsolution/HintHandlerProdImpl.kt
index 74bea300c55..a4096d930a7 100644
--- a/domain/src/main/java/org/oppia/android/domain/hintsandsolution/HintHandlerProdImpl.kt
+++ b/domain/src/main/java/org/oppia/android/domain/hintsandsolution/HintHandlerProdImpl.kt
@@ -12,6 +12,7 @@ import org.oppia.android.app.model.HelpIndex.IndexTypeCase.NEXT_AVAILABLE_HINT_I
 import org.oppia.android.app.model.HelpIndex.IndexTypeCase.SHOW_SOLUTION
 import org.oppia.android.app.model.State
 import org.oppia.android.util.threading.BackgroundDispatcher
+import java.util.concurrent.atomic.AtomicInteger
 import java.util.concurrent.locks.ReentrantLock
 import javax.inject.Inject
 import kotlin.concurrent.withLock
@@ -65,7 +66,7 @@ class HintHandlerProdImpl private constructor(
 
   private var trackedWrongAnswerCount = 0
   private lateinit var pendingState: State
-  private var hintSequenceNumber = 0
+  private var hintSequenceNumber = AtomicInteger(0)
   private var lastRevealedHintIndex = -1
 
   private var latestAvailableHintIndex = -1
@@ -186,7 +187,7 @@ class HintHandlerProdImpl private constructor(
     // Cancel any potential pending hints by advancing the sequence number. Note that this isn't
     // reset to 0 to ensure that all previous hint tasks are cancelled, and new tasks can be
     // scheduled without overlapping with past sequence numbers.
-    hintSequenceNumber++
+    hintSequenceNumber.incrementAndGet()
   }
 
   private fun maybeScheduleShowHint(wrongAnswerCount: Int = trackedWrongAnswerCount) {
@@ -295,17 +296,17 @@ class HintHandlerProdImpl private constructor(
     // Return the index of the first unrevealed hint, or the length of the list if all have been
     // revealed.
     val hintList = pendingState.interaction.hintList
-    val solution = pendingState.interaction.solution
 
     val hasHints = hintList.isNotEmpty()
-    val hasHelp = hasHints || solution.hasCorrectAnswer()
+    val hasSolution = pendingState.hasSolution()
+    val hasHelp = hasHints || hasSolution
     val lastUnrevealedHintIndex = lastRevealedHintIndex + 1
 
     return if (!hasHelp) {
       HelpIndex.getDefaultInstance()
     } else if (hasHints && lastUnrevealedHintIndex < hintList.size) {
       HelpIndex.newBuilder().setNextAvailableHintIndex(lastUnrevealedHintIndex).build()
-    } else if (solution.hasCorrectAnswer() && !solutionIsRevealed) {
+    } else if (hasSolution && !solutionIsRevealed) {
       HelpIndex.newBuilder().setShowSolution(true).build()
     } else {
       HelpIndex.newBuilder().setEverythingRevealed(true).build()
@@ -317,7 +318,7 @@ class HintHandlerProdImpl private constructor(
    * cancelling any previously pending hints initiated by calls to this method.
    */
   private fun scheduleShowHint(delayMs: Long, helpIndexToShow: HelpIndex) {
-    val targetSequenceNumber = ++hintSequenceNumber
+    val targetSequenceNumber = hintSequenceNumber.incrementAndGet()
     backgroundCoroutineScope.launch {
       delay(delayMs)
       handlerLock.withLock {
@@ -331,12 +332,12 @@ class HintHandlerProdImpl private constructor(
    * pending hints initiated by calls to [scheduleShowHint].
    */
   private fun showHintImmediately(helpIndexToShow: HelpIndex) {
-    showHint(++hintSequenceNumber, helpIndexToShow)
+    showHint(hintSequenceNumber.incrementAndGet(), helpIndexToShow)
   }
 
   private fun showHint(targetSequenceNumber: Int, nextHelpIndexToShow: HelpIndex) {
     // Only finish this timer if no other hints were scheduled and no cancellations occurred.
-    if (targetSequenceNumber == hintSequenceNumber) {
+    if (targetSequenceNumber == hintSequenceNumber.get()) {
       val previousHelpIndex = computeCurrentHelpIndex()
 
       when (nextHelpIndexToShow.indexTypeCase) {
@@ -376,7 +377,7 @@ class HintHandlerProdImpl private constructor(
 }
 
 /** Returns whether this state has a solution to show. */
-private fun State.hasSolution(): Boolean = interaction.solution.hasCorrectAnswer()
+private fun State.hasSolution(): Boolean = interaction.hasSolution()
 
 /** Returns whether this state has help that the user can see. */
 internal fun State.offersHelp(): Boolean = interaction.hintList.isNotEmpty() || hasSolution()
diff --git a/domain/src/main/java/org/oppia/android/domain/util/StateRetriever.kt b/domain/src/main/java/org/oppia/android/domain/util/StateRetriever.kt
index 16a374e7168..bfe0815af2f 100644
--- a/domain/src/main/java/org/oppia/android/domain/util/StateRetriever.kt
+++ b/domain/src/main/java/org/oppia/android/domain/util/StateRetriever.kt
@@ -60,36 +60,26 @@ class StateRetriever @Inject constructor() {
 
   // Creates an interaction from JSON
   private fun createInteractionFromJson(interactionJson: JSONObject): Interaction {
-    return Interaction.newBuilder()
-      .setId(interactionJson.getStringFromObject("id"))
-      .addAllAnswerGroups(
+    return Interaction.newBuilder().apply {
+      id = interactionJson.getStringFromObject("id")
+      addAllAnswerGroups(
         createAnswerGroupsFromJson(
           interactionJson.getJSONArray("answer_groups"),
           interactionJson.getStringFromObject("id")
         )
       )
-      .setDefaultOutcome(
-        createOutcomeFromJson(
-          interactionJson.optJSONObject("default_outcome")
-        )
-      )
-      .putAllCustomizationArgs(
+      defaultOutcome = createOutcomeFromJson(interactionJson.optJSONObject("default_outcome"))
+      putAllCustomizationArgs(
         createCustomizationArgsMapFromJson(
           interactionJson.getJSONObject("customization_args"),
           interactionJson.getStringFromObject("id")
         )
       )
-      .addAllHint(
-        createListOfHintsFromJson(
-          interactionJson.getJSONArray("hints")
-        )
-      )
-      .setSolution(
-        createSolutionFromJson(
-          interactionJson.optJSONObject("solution")
-        )
-      )
-      .build()
+      addAllHint(createListOfHintsFromJson(interactionJson.getJSONArray("hints")))
+
+      // Only set the solution if one has been defined.
+      createSolutionFromJson(interactionJson.optJSONObject("solution"))?.let { solution = it }
+    }.build()
   }
 
   // Creates the list of answer group objects from JSON
@@ -159,30 +149,33 @@ class StateRetriever @Inject constructor() {
   }
 
   // Creates a solution object from JSON
-  private fun createSolutionFromJson(solutionJson: JSONObject?): Solution {
-    if (solutionJson == null) {
-      return Solution.getDefaultInstance()
+  private fun createSolutionFromJson(optionalSolutionJson: JSONObject?): Solution? {
+    return optionalSolutionJson?.let { solutionJson ->
+      return Solution.newBuilder().apply {
+        correctAnswer = createCorrectAnswer(solutionJson)
+        explanation = parseSubtitledHtml(solutionJson.getJSONObject("explanation"))
+        answerIsExclusive = solutionJson.getBoolean("answer_is_exclusive")
+      }.build()
     }
-    return Solution.newBuilder().apply {
-      correctAnswer = createCorrectAnswer(solutionJson)
-      explanation = parseSubtitledHtml(solutionJson.getJSONObject("explanation"))
-      answerIsExclusive = solutionJson.getBoolean("answer_is_exclusive")
-    }.build()
   }
 
   private fun createCorrectAnswer(containerObject: JSONObject): CorrectAnswer {
     val correctAnswerObject = containerObject.optJSONObject("correct_answer")
-    return if (correctAnswerObject != null) {
-      CorrectAnswer.newBuilder()
-        .setNumerator(correctAnswerObject.getInt("numerator"))
-        .setDenominator(correctAnswerObject.getInt("denominator"))
-        .setWholeNumber(correctAnswerObject.getInt("wholeNumber"))
-        .setIsNegative(correctAnswerObject.getBoolean("isNegative"))
-        .build()
-    } else {
-      CorrectAnswer.newBuilder()
-        .setCorrectAnswer(containerObject.getStringFromObject("correct_answer"))
-        .build()
+    return when {
+      correctAnswerObject != null -> {
+        CorrectAnswer.newBuilder()
+          .setNumerator(correctAnswerObject.getInt("numerator"))
+          .setDenominator(correctAnswerObject.getInt("denominator"))
+          .setWholeNumber(correctAnswerObject.getInt("wholeNumber"))
+          .setIsNegative(correctAnswerObject.getBoolean("isNegative"))
+          .build()
+      }
+      containerObject.optString("correct_answer", /* fallback= */ null) != null -> {
+        CorrectAnswer.newBuilder()
+          .setCorrectAnswer(containerObject.getStringFromObject("correct_answer"))
+          .build()
+      }
+      else -> CorrectAnswer.getDefaultInstance() // For incompatible types.
     }
   }
 
diff --git a/domain/src/test/java/org/oppia/android/domain/hintsandsolution/HintHandlerProdImplTest.kt b/domain/src/test/java/org/oppia/android/domain/hintsandsolution/HintHandlerProdImplTest.kt
index de5ab65385a..d24fe070cbe 100644
--- a/domain/src/test/java/org/oppia/android/domain/hintsandsolution/HintHandlerProdImplTest.kt
+++ b/domain/src/test/java/org/oppia/android/domain/hintsandsolution/HintHandlerProdImplTest.kt
@@ -87,6 +87,11 @@ class HintHandlerProdImplTest {
       "test_single_interactive_state_exp_with_hints_and_solution"
     )
   }
+  private val expWithSolutionMissingCorrectAnswer by lazy {
+    explorationRetriever.loadExploration(
+      "test_single_interactive_state_exp_with_solution_missing_answer"
+    )
+  }
 
   @Before
   fun setUp() {
@@ -1908,6 +1913,48 @@ class HintHandlerProdImplTest {
     )
   }
 
+  @Test
+  fun testGetCurrentHelpIndex_onlySolution_missingCorrectAnswer_isEmpty() {
+    val state = expWithSolutionMissingCorrectAnswer.getInitialState()
+    hintHandler.startWatchingForHintsInNewState(state)
+
+    val helpIndex = hintHandler.getCurrentHelpIndex()
+
+    assertThat(helpIndex).isEqualToDefaultInstance()
+  }
+
+  @Test
+  fun testGetCurrentHelpIndex_onlySolution_missingCorrectAnswer_twoWrongAnswers_canShowSolution() {
+    val state = expWithSolutionMissingCorrectAnswer.getInitialState()
+    hintHandler.startWatchingForHintsInNewState(state)
+    hintHandler.handleWrongAnswerSubmission(wrongAnswerCount = 1)
+    hintHandler.handleWrongAnswerSubmission(wrongAnswerCount = 2)
+
+    val helpIndex = hintHandler.getCurrentHelpIndex()
+
+    assertThat(helpIndex).isEqualTo(
+      HelpIndex.newBuilder().apply {
+        showSolution = true
+      }.build()
+    )
+  }
+
+  @Test
+  fun testGetCurrentHelpIndex_onlySolution_missingCorrectAnswer_triggeredAndShown_allRevealed() {
+    val state = expWithSolutionMissingCorrectAnswer.getInitialState()
+    hintHandler.startWatchingForHintsInNewState(state)
+    waitFor60Seconds()
+    hintHandler.viewSolution()
+
+    val helpIndex = hintHandler.getCurrentHelpIndex()
+
+    assertThat(helpIndex).isEqualTo(
+      HelpIndex.newBuilder().apply {
+        everythingRevealed = true
+      }.build()
+    )
+  }
+
   private fun Exploration.getInitialState(): State = statesMap.getValue(initStateName)
 
   private fun triggerFirstHint() = waitFor60Seconds()
diff --git a/oppia_android_application.bzl b/oppia_android_application.bzl
index cdebac05354..2627fb86b8c 100644
--- a/oppia_android_application.bzl
+++ b/oppia_android_application.bzl
@@ -97,6 +97,47 @@ def _bundle_module_zip_into_deployable_aab_impl(ctx):
         runfiles = ctx.runfiles(files = [output_file]),
     )
 
+def _package_metadata_into_deployable_aab_impl(ctx):
+    output_aab_file = ctx.outputs.output_aab_file
+    input_aab_file = ctx.attr.input_aab_file.files.to_list()[0]
+    proguard_map_file = ctx.attr.proguard_map_file.files.to_list()[0]
+
+    command = """
+    # Extract deployable AAB to working directory.
+    WORKING_DIR=$(mktemp -d)
+    echo $WORKING_DIR
+    cp {0} $WORKING_DIR/temp.aab || exit 255
+
+    # Change the permissions of the AAB copy so that it can be overwritten later.
+    chmod 755 $WORKING_DIR/temp.aab || exit 255
+
+    # Create directory needed for storing bundle metadata.
+    mkdir -p $WORKING_DIR/BUNDLE-METADATA/com.android.tools.build.obfuscation
+
+    # Copy over the Proguard map file.
+    cp {1} $WORKING_DIR/BUNDLE-METADATA/com.android.tools.build.obfuscation/proguard.map || exit 255
+
+    $ Repackage the AAB file into the destination.
+    DEST_FILE_PATH="$(pwd)/{2}"
+    cd $WORKING_DIR
+    zip -Dur temp.aab BUNDLE-METADATA || exit 255
+    cp temp.aab $DEST_FILE_PATH || exit 255
+    """.format(input_aab_file.path, proguard_map_file.path, output_aab_file.path)
+
+    # Reference: https://docs.bazel.build/versions/main/skylark/lib/actions.html#run_shell.
+    ctx.actions.run_shell(
+        outputs = [output_aab_file],
+        inputs = ctx.files.input_aab_file + ctx.files.proguard_map_file,
+        tools = [],
+        command = command,
+        mnemonic = "PackageMetadataIntoDeployableAAB",
+        progress_message = "Generating deployable AAB",
+    )
+    return DefaultInfo(
+        files = depset([output_aab_file]),
+        runfiles = ctx.runfiles(files = [output_aab_file]),
+    )
+
 def _generate_apks_and_install_impl(ctx):
     input_file = ctx.attr.input_file.files.to_list()[0]
     debug_keystore_file = ctx.attr.debug_keystore.files.to_list()[0]
@@ -157,7 +198,7 @@ def _generate_apks_and_install_impl(ctx):
 _convert_apk_to_module_aab = rule(
     attrs = {
         "input_file": attr.label(
-            allow_files = True,
+            allow_single_file = True,
             mandatory = True,
         ),
         "output_file": attr.output(
@@ -175,7 +216,7 @@ _convert_apk_to_module_aab = rule(
 _convert_module_aab_to_structured_zip = rule(
     attrs = {
         "input_file": attr.label(
-            allow_files = True,
+            allow_single_file = True,
             mandatory = True,
         ),
         "output_file": attr.output(
@@ -188,11 +229,11 @@ _convert_module_aab_to_structured_zip = rule(
 _bundle_module_zip_into_deployable_aab = rule(
     attrs = {
         "input_file": attr.label(
-            allow_files = True,
+            allow_single_file = True,
             mandatory = True,
         ),
         "config_file": attr.label(
-            allow_files = True,
+            allow_single_file = True,
             mandatory = True,
         ),
         "output_file": attr.output(
@@ -207,14 +248,31 @@ _bundle_module_zip_into_deployable_aab = rule(
     implementation = _bundle_module_zip_into_deployable_aab_impl,
 )
 
+_package_metadata_into_deployable_aab = rule(
+    attrs = {
+        "input_aab_file": attr.label(
+            allow_single_file = True,
+            mandatory = True,
+        ),
+        "proguard_map_file": attr.label(
+            allow_single_file = True,
+            mandatory = True,
+        ),
+        "output_aab_file": attr.output(
+            mandatory = True,
+        ),
+    },
+    implementation = _package_metadata_into_deployable_aab_impl,
+)
+
 _generate_apks_and_install = rule(
     attrs = {
         "input_file": attr.label(
-            allow_files = True,
+            allow_single_file = True,
             mandatory = True,
         ),
         "debug_keystore": attr.label(
-            allow_files = True,
+            allow_single_file = True,
             mandatory = True,
         ),
         "_bundletool_tool": attr.label(
@@ -227,22 +285,27 @@ _generate_apks_and_install = rule(
     implementation = _generate_apks_and_install_impl,
 )
 
-def oppia_android_application(name, config_file, **kwargs):
+def oppia_android_application(name, config_file, proguard_generate_mapping, **kwargs):
     """
     Creates an Android App Bundle (AAB) binary with the specified name and arguments.
 
     Args:
-        name: str. The name of the Android App Bundle to build. This will corresponding to the name of
-            the generated .aab file.
+        name: str. The name of the Android App Bundle to build. This will corresponding to the name
+            of the generated .aab file.
         config_file: target. The path to the .pb.json bundle configuration file for this build.
-        **kwargs: additional arguments. See android_binary for the exact arguments that are available.
+        proguard_generate_mapping: boolean. Whether to perform a Proguard optimization step &
+            generate Proguard mapping corresponding to the obfuscation step.
+        **kwargs: additional arguments. See android_binary for the exact arguments that are
+            available.
     """
     binary_name = "%s_binary" % name
     module_aab_name = "%s_module_aab" % name
     module_zip_name = "%s_module_zip" % name
+    deployable_aab_name = "%s_deployable" % name
     native.android_binary(
         name = binary_name,
         tags = ["manual"],
+        proguard_generate_mapping = proguard_generate_mapping,
         **kwargs
     )
     _convert_apk_to_module_aab(
@@ -257,13 +320,30 @@ def oppia_android_application(name, config_file, **kwargs):
         output_file = "%s.zip" % module_zip_name,
         tags = ["manual"],
     )
-    _bundle_module_zip_into_deployable_aab(
-        name = name,
-        input_file = ":%s.zip" % module_zip_name,
-        config_file = config_file,
-        output_file = "%s.aab" % name,
-        tags = ["manual"],
-    )
+    if proguard_generate_mapping:
+        _bundle_module_zip_into_deployable_aab(
+            name = deployable_aab_name,
+            input_file = ":%s.zip" % module_zip_name,
+            config_file = config_file,
+            output_file = "%s.aab" % deployable_aab_name,
+            tags = ["manual"],
+        )
+        _package_metadata_into_deployable_aab(
+            name = name,
+            input_aab_file = ":%s.aab" % deployable_aab_name,
+            proguard_map_file = ":%s_proguard.map" % binary_name,
+            output_aab_file = "%s.aab" % name,
+            tags = ["manual"],
+        )
+    else:
+        # No extra package step is needed if there's no Proguard map file.
+        _bundle_module_zip_into_deployable_aab(
+            name = name,
+            input_file = ":%s.zip" % module_zip_name,
+            config_file = config_file,
+            output_file = "%s.aab" % name,
+            tags = ["manual"],
+        )
 
 def declare_deployable_application(name, aab_target):
     """
diff --git a/scripts/assets/file_content_validation_checks.textproto b/scripts/assets/file_content_validation_checks.textproto
index 0700602b594..489617c1f11 100644
--- a/scripts/assets/file_content_validation_checks.textproto
+++ b/scripts/assets/file_content_validation_checks.textproto
@@ -251,3 +251,9 @@ file_content_checks {
   exempted_file_patterns: "scripts/.+?\\.kt"
   exempted_file_patterns: "utility/src/(?:((main)|(test)))/java/org/oppia/android/util/locale/.+?\\.kt"
 }
+file_content_checks {
+  file_path_regex: ".+?.kt"
+  prohibited_content_regex: "kotlin\\.properties\\.Delegates"
+  failure_message: "Don't use Delegates; use a lateinit var or nullable primitive var default-initialized to null, instead. Delegates uses reflection internally, have a non-trivial initialization cost, and can cause breakages on KitKat devices. See #3939 for more context."
+  exempted_file_name: "scripts/src/javatests/org/oppia/android/scripts/regex/RegexPatternValidationCheckTest.kt"
+}
diff --git a/scripts/src/javatests/org/oppia/android/scripts/regex/RegexPatternValidationCheckTest.kt b/scripts/src/javatests/org/oppia/android/scripts/regex/RegexPatternValidationCheckTest.kt
index 316fd0ef432..3f576389c91 100644
--- a/scripts/src/javatests/org/oppia/android/scripts/regex/RegexPatternValidationCheckTest.kt
+++ b/scripts/src/javatests/org/oppia/android/scripts/regex/RegexPatternValidationCheckTest.kt
@@ -115,6 +115,10 @@ class RegexPatternValidationCheckTest {
     "Don't perform date/time formatting directly. Instead, use OppiaLocale."
   private val useJavaLocaleErrorMessage =
     "Don't use Locale directly. Instead, use LocaleController, or OppiaLocale & its subclasses."
+  private val doNotUseKotlinDelegatesErrorMessage =
+    "Don't use Delegates; use a lateinit var or nullable primitive var default-initialized to" +
+      " null, instead. Delegates uses reflection internally, have a non-trivial initialization" +
+      " cost, and can cause breakages on KitKat devices. See #3939 for more context."
   private val wikiReferenceNote =
     "Refer to https://github.com/oppia/oppia-android/wiki/Static-Analysis-Checks" +
       "#regexpatternvalidation-check for more details on how to fix this."
@@ -1462,6 +1466,27 @@ class RegexPatternValidationCheckTest {
       )
   }
 
+  @Test
+  fun testFileContent_kotlinDelegatesImport_fileContentIsNotCorrect() {
+    val prohibitedContent = "kotlin.properties.Delegates"
+    tempFolder.newFolder("testfiles", "domain", "src", "main")
+    val stringFilePath = "domain/src/main/SomeController.kt"
+    tempFolder.newFile("testfiles/$stringFilePath").writeText(prohibitedContent)
+
+    val exception = assertThrows(Exception::class) {
+      runScript()
+    }
+
+    assertThat(exception).hasMessageThat().contains(REGEX_CHECK_FAILED_OUTPUT_INDICATOR)
+    assertThat(outContent.toString().trim())
+      .isEqualTo(
+        """
+        $stringFilePath:1: $doNotUseKotlinDelegatesErrorMessage
+        $wikiReferenceNote
+        """.trimIndent()
+      )
+  }
+
   @Test
   fun testFileContent_nonCompatDrawables_fileContentIsNotCorrect() {
     val prohibitedContent =
diff --git a/utility/src/main/java/org/oppia/android/util/logging/firebase/BUILD.bazel b/utility/src/main/java/org/oppia/android/util/logging/firebase/BUILD.bazel
index 3ba7077b23e..3a69f05bcf2 100644
--- a/utility/src/main/java/org/oppia/android/util/logging/firebase/BUILD.bazel
+++ b/utility/src/main/java/org/oppia/android/util/logging/firebase/BUILD.bazel
@@ -54,10 +54,13 @@ kt_android_library(
 )
 
 kt_android_library(
-    name = "debug_impl",
+    name = "debug_event_logger",
     srcs = [
         "DebugEventLogger.kt",
     ],
+    visibility = [
+        "//app:__pkg__",
+    ],
     deps = [
         "//model:event_logger_java_proto_lite",
         "//third_party:javax_inject_javax_inject",
@@ -73,7 +76,7 @@ kt_android_library(
     visibility = ["//:oppia_prod_module_visibility"],
     deps = [
         ":dagger",
-        ":debug_impl",
+        ":debug_event_logger",
         ":firebase_exception_logger",
     ],
 )
diff --git a/utility/src/main/java/org/oppia/android/util/parser/svg/SvgPictureDrawable.kt b/utility/src/main/java/org/oppia/android/util/parser/svg/SvgPictureDrawable.kt
index c0957cfce4a..38d8f81c438 100644
--- a/utility/src/main/java/org/oppia/android/util/parser/svg/SvgPictureDrawable.kt
+++ b/utility/src/main/java/org/oppia/android/util/parser/svg/SvgPictureDrawable.kt
@@ -1,5 +1,6 @@
 package org.oppia.android.util.parser.svg
 
+import android.annotation.SuppressLint
 import android.content.Context
 import android.graphics.Bitmap
 import android.graphics.Canvas
@@ -9,6 +10,7 @@ import android.graphics.Picture
 import android.graphics.PixelFormat
 import android.graphics.Rect
 import android.graphics.drawable.Drawable
+import android.os.Build
 import android.text.TextPaint
 import org.oppia.android.util.parser.image.BitmapBlurrer
 import org.oppia.android.util.parser.image.ImageTransformation
@@ -41,7 +43,7 @@ abstract class SvgPictureDrawable(
       // Save current transformation state.
       save()
 
-      if (scalableVectorGraphic.hasTransformations()) {
+      if (scalableVectorGraphic.shouldBeRenderedAsBitmap()) {
         bitmap?.let { bitmap ->
           drawBitmap(bitmap, /* src= */ null, bounds, bitmapPaint)
         }
@@ -90,7 +92,7 @@ abstract class SvgPictureDrawable(
       scalableVectorGraphic.renderToTextPicture(it)
     } ?: scalableVectorGraphic.renderToBlockPicture()
     intrinsicSize = scalableVectorGraphic.computeSizeSpecs(textPaint)
-    if (scalableVectorGraphic.hasTransformations()) {
+    if (scalableVectorGraphic.shouldBeRenderedAsBitmap()) {
       recomputeBitmap()
     }
   }
@@ -120,4 +122,13 @@ abstract class SvgPictureDrawable(
   }
 }
 
+private fun ScalableVectorGraphic.shouldBeRenderedAsBitmap() =
+  hasTransformations() || isUsingAndroidSdkWithSvgRenderingIssues()
+
 private fun ScalableVectorGraphic.hasTransformations() = transformations.isNotEmpty()
+
+// TODO(#3961): Remove this & instead rely on native SVG rendering for older SDK versions.
+// See #3938 for context on why these OS versions are being forced to bitmap rendering.
+@SuppressLint("ObsoleteSdkInt") // Incorrect warning.
+private fun isUsingAndroidSdkWithSvgRenderingIssues() =
+  Build.VERSION.SDK_INT <= Build.VERSION_CODES.M
diff --git a/version.bzl b/version.bzl
index 9ef6da3d3d2..e943f7fa5ab 100644
--- a/version.bzl
+++ b/version.bzl
@@ -5,7 +5,7 @@ Defines the latest version of the Oppia Android app.
 MAJOR_VERSION = 0
 MINOR_VERSION = 6
 
-OPPIA_DEV_KITKAT_VERSION_CODE = 10
-OPPIA_DEV_VERSION_CODE = 11
-OPPIA_ALPHA_KITKAT_VERSION_CODE = 12
-OPPIA_ALPHA_VERSION_CODE = 13
+OPPIA_DEV_KITKAT_VERSION_CODE = 14
+OPPIA_DEV_VERSION_CODE = 15
+OPPIA_ALPHA_KITKAT_VERSION_CODE = 16
+OPPIA_ALPHA_VERSION_CODE = 17