A: 8 - AppModule.java

AppModule.java

@Module(includes = AndroidInjectionModule.class,
        subcomponents = {
                MainActivitySubcomponent.class,
                Example1ActivitySubcomponent.class,
                Example2ActivitySubcomponent.class,
                Example3ActivitySubcomponent.class
        })
abstract class AppModule {
    ...
    
    // TODO (ContributesAndroidInjector) remove this in favor of @ContributesAndroidInjector
    @Binds
    @IntoMap
    @ActivityKey(Example3Activity.class)
    abstract AndroidInjector.Factory<? extends Activity>
    example3ActivityInjectorFactory(Example3ActivitySubcomponent.Builder builder);
}