为使程序的输出结果为: Base:: fun 那么应在下列程序画线处填入的正确语句是( )。 #include <iostream> using namespace std; class Base { public:void fun (){ cout<<"Base: :fun"<<end1;} }; class Derived : public Base { public:void fun ( ){ cout<<"Derived: :fun"<<end1;} }; int main ( ) {Base a,*pb;Derived b;_________;pb->fun(); //调用基类的成员函数 fun()return 0 ; }
A.pb=&a
B.pb=b
C.pb=&b
D.pb=&Base