The skirt _______ she is wearing today was a birthday present from her mother. [ ]

A. this

B. whose

C. what

D. that

有以下程序　　void f( int　y,int　*x)　　{　y=y+*x;　*x=*x+y;}　　　main(　)　　{　int　x=2,y=4; 　　　f(y,&x); 　　　printf(“%d %d\n”,x,y);} 　　执行后输出的结果是【 】。