单选题 He didn't thank me for the present. That is ______ annoyed me.
  • A. which
  • B. that
  • C. what
  • D. how
【正确答案】 C
【答案解析】[解析] 这是由关系代词what引起的表语从句。what：在从句中作主语，表示“所……的(东西或事情)”。其他三项均不能在此引起表语从句。