Diesel engines burn as much as 30% less fuel than gasoline engines of comparable size, as well as emitting far less carbon dioxide gas and far fewer of the other gases that have been implicated in global warming.

A. Same
B. of comparable size as well as emit far less carbon dioxide gas and far fewer of the other gas having
C. of comparable size, and also they emit far fewer carbon dioxide and other gases that have
D. that have a comparable size , and also they emit far less carbon dioxide and other gases that have
E. that have a comparable size, as well as emitting far fewer carbon dioxide and other gases having.

OA is A. I was not sure why fewer of the other gases is correct. I thought that gas is uncountable noun and should use less.

Can someone clarify this?

Thanks.

Refer to the thread on the same http://www.manhattangmat.com/forums/post13579.html.

thanks tathagat!