—Boys and girls, please have a seat and ____.

—Thank you.

A．help yourselves

B．help yourself

C．helps yourself

D．help you

有以下程序
main()
int k=5;
while(-k) printf("%d",k-=3);
printf("\n");

执行后的输出结果是______。
A) 1B) 2 C) 4 D) 死循环