单选题
The parents were much kinder to their youngest child than they were to the others, ______, of course, made the others jealous.
【正确答案】
A
【答案解析】[解析] 本题测试非限定性定语从句的用法。本句缺少一个连接词，用以指代前面整个句子，在从句中做主语，故应选which。that不能引导非限定性定语从句；what不能引导定语从句；who是指代人，不能指代事物。