Helen was much kinder to her youngest son than to the others, , of course, made the others envy him.
A. who
B. which
C. what
D. that
网友回答
A. who
(答案→)B. which
C. what
D. that
解析：句意：海伦对她的最小的儿子比对其他的孩子要好得多，这使其他的人很是嫉妒。that和 what不能引导非限制性定语从句；这是非限制性定语从句，先行词是前面的句子，故排除A，故选B。