单项选择题

有如下程序:
#include<iostream>
using namespace std;
class Base
protected:
Base()cout<<’Base’;
Base(char c)cout<<c;
;
class Derived:public Base
public:
Derived(char c)cout<<c;
;
int main()
Derived d(’Derived’);
return 0;
执行这个程序屏幕上将显示输出( )。

A.Derived
B.DerivedBase
C.BaseDerived
D.DerivedDerived