有如下类声明: class MyBASE{ int k; public: void set(iht n){k=n;}

有如下类声明： class MyBASE{ int k; public: void set(iht n){k=n;} int get()coast{return k;} }; class MyDERIVED:pnoted My BASE { protected: int j; public: void set(int m，int n){MyBASE::set(m);j=n;} int get()const{return MyBASE::get()+j;} }; 则类MyDERIVED中保护的数据成员和成员函数的个数是

A．4

B．3

C．2

D．1