问下as well as 的用法

kkbear

Diesel engines burn as much as 30 percent 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) of comparable size, as well as emitting far less carbon dioxide gas and far fewer of the other gases that have
(B) of comparable size, as well as emit far less carbon dioxide gas and far fewer of the other gases 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 gas and other gases that have
(E) that have a comparable size, as well as emitting far fewer carbon dioxide and other gases having

答案是A，不是很明白，为什么as well as后面跟doing，不应该和前面并列的吗？

zliycdr

Prep Notes版上我遇到两次了，都是A do B, as well as doing C, 再次证明了as well as和and的区别：
and 强调完全并列平行，而as well as则更多地focus on从属关系~

sophiequeen

谢谢楼上！