—Catherine, I have cleaned the room for you.—Thanks. You ______

—Catherine, I have cleaned the room for you.—Thanks. You ______ it. I could manage it myself.
A、needn’t do
B、needn’t have done
C、mustn’t do
D、shouldn’t have done
【正确答案】：B
【题目解析】：句子的语境是：“我自己能做”，所以“你本不必做的”。排除CD，根据前面一句中的 have cleaned 可知，动作已经发生，所以此处谈论的是一个过去情况，故选 needn’t have done