单选题

class A{&nbsp public: &nbsp &nbsp ...

Question

class A{ 
public:
    virtual void say(void) {
        cout<<"A"<<endl
    }
}
class B : public A{
public:
    void say(void){
        cout<<"B"<<endl
    }
}
class C : public B{
public:
    void say(void){
        cout<<"C"<<endl
    }
}
C * pc = new C
A * pa = pc
pa->say()

以上程序输出（）

A. A

B. B

C. C

D. 都不是