求教一道GWD，哪位大侠帮帮忙？谢了先

Sulfur dioxide, a major contributor to acid rain, is an especially serious pollutant because it diminishes the respiratory system to deal with all other pollutants.

D a specially serious pollutant because it diminishes the capability of the respiratory system to deal

答案是A但我觉得D也对阿。请大侠们帮帮忙吧，谢谢。

ability（或capability) 后面应紧跟to deal with all other pollutants。D如果改成diminishes the respiratory system’s capability那还可以考虑。