Given the following class class MyNumber { private int num = 5; public MyNumber(int num) { this.num = num; } public int getNum() { return num; } public void setNum(int num) { this.num = num; } } What is output after the executation of following code? MyNumber obj1 = new MyNumber(); MyNumber obj2 = new MyNumber(10); obj2 = obj1; obj2.setNum(20); System.out.println(obj1.getNum() + “,” + obj2.getNum());
A．5, 20
B．5, 10
C．20,20
D．编译错误