--Well done, Jack !
--Thanks. But given more time, I it better.
A. shouldn't have done
B. could have done
C. might not do
D. could do
网友回答
A. shouldn't have done
(答案→)B. could have done
C. might not do
D. could do
解析：本题为情态动词的考查。根据题干得知动作已经发生，情态动词+动词的完成式表示对过去的推测。