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<<end1; }

A.12 12
B.12 21
C.21 12
D.21 11