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(p＜q){f(p,q);p++；q-；}for(i=0；i＜8；i++)printf( %d, a[i]);}程序运行后的输出结果是【 】。
A．823,4,5,6,7,1,
B．5,6,7,8,12,3,4,
C．1,2,3,4,5,6,7,8,
D．8,7,6,5,4,3,2,1,