— He ought to have been warned of the danger. — , but he just wouldn’t listen to me.A. So

— He ought to have been warned of the danger.
— , but he just wouldn’t listen to me.
A. So ought he
B. So he was
C. So was he
D. So he had

@@A. So ought he@@B. So he was@@C. So was he@@D. So he had
解析：
ought to have been warned of表示“本应该被告诫有危险”，是对过去动作的推测，因此回答也应该用过去时。A的构成形式不对。而So he was必须与第一句谓语动词have been一致。

我明天再问问老师，叫他解释下这个问题