一道英语语法题,

问题描述:

一道英语语法题,
Mary ____ clean out the room last Monday,but she was too busy that day.
A.has intended to
B.was intended to
c .intended to
d.had intended to
选哪一个?为什么?

这是考察虚拟语气.应该选D
与过去所发生的事情相反,应该用过去完成时态,玛丽上周一本应该打扫屋子的,但是那天她太忙了.