下列哪一种物质是汽车尾气中主要污染物之一

A、H[img=~/QImg/2013-10-14-11-46-19/image002.jpg]S
B、SO[img=~/QImg/2013-10-14-11-46-19/image002.jpg]
C、NO[img=~/QImg/2013-10-14-11-46-19/image001.jpg]
D、O[img=~/QImg/2013-10-14-11-46-19/image003.jpg]
E、颗粒物