Did Jack come back early last night?

问题描述:

Did Jack come back early last night?
—Yes.It was not yet eight o’clock he arrived home.(Fujian2005)
B.when C.that
选什么 为什么
我如果选C当成强调句哪里不对?

如果这里是个强调句的话,那么去掉it was和that剩下的部分是一个句子,但事实上不是
强调句最主要的特征就是去掉it is和that还能组成句子