It was how the young man had learned five foreign languages _____attracted the audience's interest.那为什么不选 C,理解成主语从句的后置

问题描述:

It was how the young man had learned five foreign languages _____attracted the audience's interest.
那为什么不选 C,理解成主语从句的后置

that
how 引导的从句做整个句子的宾语,而that引导的是同位语从句,同时that在从句中做主语
这个年轻人是如何学好5门外语的,这引起了观众的(极大)兴趣。

that
强调句