The traditional view is __ we sleep because our brain is“programmed ”to make us do so.

问题描述:

The traditional view is __ we sleep because our brain is“programmed ”to make us do so.
A.when B.why C.whether D.that
为什么不能选B呢?翻译不也是很通顺么

表语从句连接词用thatsorry,我自己翻译错了....