When I am down, my parents will do what every parent will do, is to hug me tighter and tell me I am the best.
A. which
B. what
C. that
D. who
网友回答
(答案→)A. which
B. what
C. that
D. who
解析：通过分析句子结构，可知这个句子中包含一个非限制性定语从句，且关系词在从句中作主语，指代前面的整个主句内容，故用which。That和what 不能引导非限制性定语从句。Who先行词应该是人。