有如下程序: #include < iostream > using namespace std; class A public : virtual void funcl() cout <<"A1" ; voidfunc2() cout<<"A2"; ; class B : public A public : void func1 () cout << " B1" ; void func2 () cout << "B2" ; ; int main()
A * p = new B ; p -> func1 () ; p -> func2 () ; delete p ; return 0 ;执行这个程序的输出结果是( )。A) B1B2 B) A1A2 C) B1A2 D) A1B2