[求助]关于as well as

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

答案是a，我想请教下nn，as well as 作连词后不是应该用emit么？另外选项b错在哪里？having been done是不是一定是错误的？最近问题比较多啊，急啊，谢谢NN的帮助啊

having been done在句子中可以有三种作用，这里having been implicated的功能也有三种可能：
1. 作为伴随结果状语 （显然与主句无因果）
2. 作为伴随动作状语，主句主语也就是emit的逻辑主语disel engines无法充当分词短语的逻辑主语
3. 就近作定语， 但现在分词的完成时态不能做定语修饰名词。

另外，as well as 是副词形式，无法做为连词来连接两个主谓结构。

as well as doing sth

of结构对称

thank you for your help! mikecello