while和as引导原因状语从句的区别,有个问题

问题描述:

while和as引导原因状语从句的区别,有个问题
_______football is a popular ball game in that country,there is unbelieably no regular league match.
A.When B.As C.While D.Despite指导一下 选B还是C?貌似答案是while,但As为什么不行?
这句话到底是什么意思? 这句是让步状语从句还是表原因?

这里要填得词的意思应该是虽然,即连词,只有While有这个用法,as 在表示虽然,尽管时,引导的让步状语从句应该要放在形容词或副词之后,如:Young as I am,I already know what career I want to follow!