问题补充：
— You for me this morning. I came over here with Michael in his car.
— Well, why didn’t you let me know earlier?
A. should have waited
B. would have waited
C. couldn’t have waited
D. needn’t have waited
答案：
A. should have waited
B. would have waited
C. couldn’t have waited
(答案→)D. needn’t have waited
解析：句意，这是两个人之间的对话。第一个人说：“今天早晨，你本来没有必要等我，我坐Michael的车过来的。” 第二个人说： “你为什么不早点让我知道。” . should have done “过去本该做而没做”； would have waited 对过去事情的假设，意思是“本来会做”；couldn’t have waited “本不能做的事却做了”；needn’t have done 表示“原本不必做的事却做了”。根据句意，这里表示“你原本不必等我，实际上你却等我了”，故选D。
