单选题 His brother had become a teacher, ______ he wanted to be.
A. who B. what C. which D. that

【正确答案】 C
【答案解析】[解析] 本题测试定语从句的用法。先行词是teacher，在这里应由which引导非限制性定语从句。本句的意思是：“他哥哥是一名教师，他也想成为一名教师。”