.12.A computer does only what people ___.

A have sb do sth 让某人做某事

have it done ,让某人或某物做什么，同是本局是个宾语从句，从句用祈使句顺序，所以答案是第一个！

这是一个被动句。前面这位兄弟说的对A have sb do sth 让某人做某 先去c ,d ，a

A
have sb do sth 让某人干某事
have sth done 比如:I have my hair cut.我把头发剪了

这两个用法不一样