选项中哪一行代码可以添加到题目中而不产生编译错误？public abstract class MyClass {     public int constInt = 5;     //add code here     public void method() {     }}

• A.public abstract void method(int a);

• B.constInt = constInt + 5;

• C.public int method();

• D.public abstract void anotherMethod() {}