Can you help me polish this code?

Good I have a RadiogGroup called rdgroup and in four RadioButton called rbtna rbtnb rbtnc and rbtnd respectively, what I try to do is that when you choose one of the raiobutton look in my database of firebase and show if it is correct or not My code is as follows:

private DatabaseReference tema;  
---------------------------------  
tema = database.getReference("Temas").child("suma").child("1");
-----------------------------------
--califica es el onclick de mi botón siguiente

public void califica(View view) {
    DatabaseReference obten=tema.child("respuesta");
    if (view.getId()== Integer.parseInt(String.valueOf(obten))){
        Toast.makeText(this, "Correcto", Toast.LENGTH_SHORT).show();
    }

    Intent i = new Intent(getApplicationContext(),restaActivity.class);
    startActivity(i);
}

my bd in firebase is the following

I get the following error

Caused by: java.lang.IllegalAccessError: Method 'void android.support.v4.content.ContextCompat.<init>()' is inaccessible to class 'com.google.firebase.iid.zzg' (declaration of 'com.google.firebase.iid.zzg' appears in /data/app/com.juegosludicos.vedette-1/split_lib_dependencies_apk.apk:classes17.dex)