下列程序的运行结果是（）
#include <iostream>
#include <cmath>
using namespace std;
class Point {
public:
Point(int X=0, int Y=0);
Point(Point &p);
int GetX() {return X;}
int GetY() {return Y;}
static int countP;
static void GetC(Point A,Point B) {
int z;
z=sqrt((B.X-A.X)*(B.X-A.X)+(B.Y-A.Y)*(B.Y-A.Y));
cout<<z<<endl;}
private:
int X,Y;
};
Point::Point(int X, int Y) {
this->X=X;
this->Y=Y;
countP++;
}
Point::Point(Point &p) {
X=p.X;
Y=p.Y;
countP++;
}
int Point::countP=0;
int main() {
Point D(3,4), *p;
Point E(D);
p = &E;
void (*q)(Point,Point) = Point::GetC;
(*q)(D, E);
return 0;
} 
