class ClassA {  public int numberOfinstances；  protected ClassA（int numberOfinstances） {  this.numberOflnstances = numberOfinstances；  }  }  public class ExtendedA extends ClassA {  private ExtendedA（int numberOfinstances） {  super（numberOflnstances）；  }  public static void main（String[] args） {  ExtendedA ext = new ExtendedA（420）；  System.out.print（ext.numberOflnstances）；  }  }  Which is true？（） 

• A、 420 is the output.
• B、 An exception is thrown at runtime.
• C、 All constructors must be declared public.
• D、 Constructors CANNOT use the private modifier.
• E、 Constructors CANNOT use the protected modifier.