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.