How I regret making the stupid mistake!Yes. Iyour doing it another way at that tim

--- How I regret making the stupid mistake!
--- Yes. I your doing it another way at that time, but in vain.
A. have suggested
B. suggested
C. would suggest
D. had suggested

A. have suggested(答案→)B. suggestedC. would suggestD. had suggested解析：试题分析:考查动词时态。从语境判断说话人已经犯了错误，所以对方给他建议也应该是过去的动作，此外at that time也是表示一般过去时的时间状语。所以正确答案为B。句意：---我是多么后悔犯了这样愚蠢的错误啊！----是的，我那时候建议过你要用另一种方法去做， 但是白费劲了。

回答的不错