有以下程序：void f(int *x,int *y){int t;t=*x;*x=*y;*y=t;}main(){int a[8]={1,2,3,4,5,6,7,8},i,*p,*q;p=a;q=&a[7];while(pA．8,2,3,4,5,6,7,1,
B．5,6,7,8,1,2,3,4,
C．1,2,3,4,5,6,7,8,
D．8,7,6,5,4,3,2,1,