请问下面这道题选什么?what i can't understand is ____ fewer and fewer chinese people are interested in chinese traditional festivals.A.why B.that但我觉得B也可以。

请问下面这道题选什么?what i can't understand is ____ fewer and fewer chinese people are interested in chinese traditional festivals.A.why B.that但我觉得B也可以。
请问下面这道题选什么?
what i can't understand is ____ fewer and fewer chinese people are interested in chinese traditional festivals.
A.why B.that
但我觉得B也可以。

请问下面这道题选什么?what i can't understand is ____ fewer and fewer chinese people are interested in chinese traditional festivals.A.why B.that但我觉得B也可以。
B
补充：个人是把understand看做“理解”,所以是不理解“事情”还是不理解“原因”才能判断选A选B（欧不是英语达人,不想误人子弟,所以建议考试还是要看权威的答案）

B

B可以是可以，但A更准确吧