能将程序补充完整的选项是
class Person
private int a;
public int change(int m)return m;
public class Teacher extends Person
public int b;
public static void main(String arg[])
Person p=new Person();
Teacher t=new Teacher();
int i;
______
A) i=m
B) i=b
C) i=p.a
D) i=p.change(50)