It rained _______ last Sunday, so they didn't go out. [ ]

A. that day    

B. a day    

C. the day    

D. all day

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．Base.fun();
B．Base::fun();
C．Base-＞fun();
D．fun();