Given:<br /> <img src="https://nimg.ppkao.com/2018-08/wenxueying/2018080114331739825.png?sign=f2a78f2bd88cd398e34f2f03bf7f1115&t=62d05659" /><br /> Which two methods, inserted individually, correctly complete the Three class?()
A、public void foo() {}
B、public int foo() { return 3; }
C、public Two foo() { return this; }
D、public One foo() { return this; }
E、public Object foo() { return this; }