单项选择题

下面程序的运行结果是
  # include <iostream.h>
  void fun(int * a,int * b)
  
    int x= * a;
    * a= * b; * b=X;
    cout << * a << * b<<" " ;
  
  void main( )
  
    int x=1, y=2;
    fun (& x,& y);
    cout < < X << y << endl;

A.12 12
B.12 21
C.21 12
D.21 21