【题目】Experts suggest that parents should let their child do tasks that he is physically and mentally capable of doing by himself, ______ will help to build a self-confident kid.
A. that B. who C. which D. what
在线课程【答案】C
【解析】试题分析：根据语境和句子结构可知该处是一个非限制性定语从句，用关系代词which指代前面句子的内容，that不能引导非限制性定语从句，who指代人，what不能引导定语从句，故选C。