单项选择题

有如下程序: #include using namespace std; class Point{ public: Point(int xx=0,int yy=0):x(xx),y(yy) { } void SetXY(int xx,int yy) { x=xx; y=yy; } protected: int x,y; }; class Circle:Point{ public: Circle(int r):radius(r) { } void Set(int r,int x,int y) { radius=r; SetXY(x,y); } //① void Print() const { cout<
A.①
B.②
C.③
D.④