It was very kind of you to do the washing-up, but you it.
A. needn’t do
B. shouldn’t do
C. mustn’t have done
D. needn’t have done
网友回答
A. needn’t do
B. shouldn’t do
C. mustn’t have done
(答案→)D. needn’t have done
解析：句意，你真好，帮我洗碗，但是你本没有必要这样做。needn’t have done “原本不必做的事却做了”，故选D。