问题补充：
Dorothy was always speaking highly of her role in the play, , of course, made the others unhappy.
A. who
B. which
C. that
D. what
答案：
A. who
(答案→)B. which
C. that
D. what
解析：考查从句，从句made the others unhappy缺少主语，所以在关系代词里找，that不引导非限制性定语从句，who先行词是人，what表示……的物或人，which指代前面一句话，句子意思“他总是说好好的演角色这是其他人不高兴”
