单项选择题

有如下程序
#include<iostream>
using nameSpace std;
class base
public:
vinual void f1()
cout<<"F1 Base";
virtual void f2()

cout<<"F2Base";

class derive:public base
void f1()
cout<<"F1Derive";
void f2(int x)
cout<<"F2Derive";

int main()
base obj1,*p;
derive obj2;
p=&obj2;
p—>f1();
p—>f2();
return 0;
执行后的输出结果是

A.F1Derive F2Base
B.F1Derive F2Derive
C.F1Base F2Base
D.F1Base F2Derive