It was very kind of you to do the washing?up, but you _______ it.

It was very kind of you to do the washing?up, but you _______ it.
a、mustn’t have done
b、 wouldn’t have done
c、 mightn’t have done
d、 didn’t have to do
选D对吗？为什么？

不可以选D，要选A
must not...have done. 意为"本不必",即已经做了某事,而时实际上不必要

请看常见的“情态动词 + have + 过去分词”的用法：

一、“must + have + 过去分词”表示对过去发生的事情或状态进行推测，语气比较坚定，通常只用于肯定句。如：

It must have rained last night, for the ground is wet.

You must have been mad to speak to the servant.

二、“can / could + have + 过去分词”表示对过去某种情况的怀疑或不确定。can和could一般用于否定句和疑问句，could的语气较can弱。如：

I didn't see her at the meeting this morning; she can't / couldn't have spoken at the meeting.

He can't have finished the work so soon.

三、“may / might + have + 过去分词”表示对已发生的动作或存在的状态进行不肯定的推测，might的语气比may弱一点。这种结构主要用于肯定句和否定句，疑问句改用can或could。如：

They may not have known it beforehand.

You might have read about it in the papers.

四、“need + have + 过去分词”表示过去做了不必做或不需要做的事情，或过去做某事纯属多余。如：

Need they have done it last week?

I needn't have bought so much wine—only five people came.