og 6

6. In virtually all types of tissue in every animal species, dioxin induces the production of enzymes that are the organism’s trying to metabolize, or render harmless, the chemical that is irritating it.

(A) trying to metabolize, or render harmless, the chemical that is irritating it

(B) trying that it metabolize, or render harmless, the. chemical irritant

(C) attempt to try to metabolize, or render harmless, such a chemical irritant

(D) attempt to try and metabolize, or render harmless, the chemical irritating it（E）

(E) attempt to metabolize, or render harmless, the chemical irritant

Don't understand OG's explanation. Why "parallelism is needed here because the sentence uses the linking verb are to equate enzymes and attempt"? 

记得在一个帖子里面一个nn说

A is B；A,B应该是对称的

具体哪个帖子，我有点找不到了，你看一下下面的连接，里面OG6有很多讨论连接，我刚说的那个NN是在这些讨论里面说的

http://forum.chasedream.com/dispbbs.asp?boardid=23&id=107432&star=1#107432

其他的选项" attempt to" try akward and wordy,不选，

A里的the production of enzymes that are the organism’s 后面用不定式感觉更好一点！