A The android:versionCode attribute in the manifest file must be incremented and the APK file must be signed with the same private key.
B The android:versionCode attribute in the manifest file must be same and the APK file must be signed with the same private key.
C The android:versionCode attribute in the manifest file must be incremented and the APK file must be signed with the new private key.
D The android:versionCode attribute in the manifest file must be same and the APK file must be signed with the new private key.