Noise pollution generally receives less attention than _________ air pollution.

我认为B不是正确的选项
因为it 代表主语, does 代表谓语, 代进去接不上了 noise pollution receives air pollution?

应该是
Noise pollution generally receives less attention than it does over air pollution. 相当于:
Noise pollution generally receives less attention than noise pollution receives over air pollution.

最常见的是: Noise pollution generally receives less attention than air pollution does.