有如下程序: #include <iostream> using namespace std; class Base {public: void fun() { cout<<"Base::fun"<<endl; } }; class Derived : public Base { public: void fun() { ______ cout<<"Derived::fun"<<endl; } }; int main() {Derived d;d.fun();return 0; } 已知其执行后的输出结果为: Base::fun Derived::fun 则程序中下划线处应填入的语句是( )。
A.Basfun();
B.Base::fun();
C.Base->fun();
D.fun();