1. class Super {
2. public float getNum() { return 3.0f; }
3. }
4.
5. public class Sub extends Super {
6.
7. }
Which method, placed at line6, causes compilation to fail?()
A. public void getNum(){}
B. public void getNum(double d){}
C. public float getNum() { return 4.0f; }
D. public double getNum(float d) { return 4.0d; }