Which of the following identifies the PRIMARY security purpose of setting android:allowBackup="false" in an Android app's manifest, and what residual risk remains even after setting this flag?

• A.It encrypts shared_prefs with a Keystore master key (AES-256-GCM); the residual risk is the debug build, and the flag is ignored there
• B.It hides the listing from Play Store search (a distribution control), and sideloaded copies remain reachable; nothing else changes
• C.It prevents ADB backup (on older Android versions) and Auto Backup; however, a rooted device or physical extraction can still access internal storage directly
• D.It blocks Auto Backup and adb backup (both vectors), leaving no residual exposure; the coverage is complete