Consider the following :

<?xml version="1.0" encoding="utf-8"?>

<menu xmlns:android="http://schemas.android.com/apk/res/android">

<item android:id="@+id/create_new"

android:title="@string/create_new" />

<item android:id="@+id/open"

android:title="@string/open" />

</menu>

public boolean onOptionsItemSelected(MenuItem item) {

switch (item.getItemId()) {

case R.id.create_new:

newFile();

return true

default:

return super.onOptionsItemSelected(item);

}
}

Upon clicking on one of the menu items, the application did not behave as intended.

Which of the following might be the cause of this problem?