GWD语法题

melody远行

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 gasses that have been implicated in global warming.

A.of comparable size, as well as emitting far less carbon dioxide gas and far fewer of the other gasses that have

B.of comparable size, as well as emit far less carbon dioxide gas and far fewer of the other gasses having

C.of comparable size, and also they emit far fewer carbon dioxide and other gasses that have

D.that have a comparable size, and also they emit far fewer of the other gasses having

E.that have a comparable size, as well as emitting far fewer of the other gasses having
我觉得A选项as well as 后面的动词形式与前面的不平行，为什么是正确选项呢？