单项选择题

如下程序的输出结果是
#include<iostream>
using namespace std;
class A
public:
virtual void f( )tout<<1;
void g( )cout<<2;

class B:public A
public:
virtual void f( )cout<<3;
void g( )cout<<4;

void show(A&

A.f( );a.g( );
int nlain( )
B b;
show(
B.;

C.14
D.32