---I was trying to carry out the plan, but I failed.

---Well, you _________, for we were uncertain it would do ________.

A．needn’t do that, in fact

B．needn’t have done, in effect

C．needn’t have, in practice

D．needn’t, in time

小儿急性咽后脓肿多为咽后壁一侧隆起。（）