--Tom used to be afraid of snakes.
-- . I thought they were scary.
A. So did I
B. So do I
C. So was I
D. So I was
网友回答
(答案→)A. So did I
B. So do I
C. So was I
D. So I was
解析：根据答语的内容I thought they were scary.，可知答案为A。在so 引导的倒装句中当so+助动词+主语（主语与上文的主语不一致），表示另一个人也是如此，表示故选A