已知类Myclass的定义如下 class MyClass{ public: void function1(MyClass& C) {cout＜＜c. data；) static void function2(MyClass& C) {cout＜＜c. data;} void function3(){cout＜＜data;} staric void function4(){cout＜＜data;} private: int data; }; 其中有编译错误的函数是( )。

A．ifstream fin; fin. open("d:\\test.txt", ios_base::in);
B．fstream fio; fio. open("d:\\test. txt”, ios_base::out);
C．ofstream fout; fout. open("d:\\test. txt”, ios_base::out);
D．ofstream fout; fout. open("d:\\test. txt”, ios_base::app);

A．
B．
C．
D．