-Are you familiar with the music?

-Yes. There was a time _____ this kind of music was quite popular.

A．that

B．when

C．with which

D．about which

按受教育程度划分，消费者群体可分为低学历、中等学历、高学历消费者群体等。此属于（）。

A．按照自然地理因素划分

B．根据人口统计因素划分

C．根据消费者心理因素划分

D．根据消费者对商品的现实反映划分