单项选择题

有如下类定义： #include using namespace std; class Point{ public: int GetXY() { return x+y; } protected: void SetXY(int a,int b) { x=a;y=b; } private: int x,y; }; class Circle:public Point{ public: int GetR() { return radius; } int GetAll() { return GetXY()+radius; } protected: void SetR(int r) { radius=r; } private: int radius; }; int main(){ Circle c; c.GetXY(); //① c.SetXY(3,4); //② c.GetR(); //③ c.GetAll(); //④ return 0; } 在标注号码的语句行中存在语法错误的是