A.A a = new A( );a.x = 3 + a.x;System.out.print(a.x);
B.A a = new A( );a.increaseBy(2);a.increaseBy(1);System.out.print(a.x);
C.A a = new A( ){public void increaseBy (int n) {super.increaseBy(n);}};a.increaseBy(4);System.out.print(a.x);
D.A a =