[E]OG-06，请指点！

Although an "-ing" verb such as trying can sometimes be used as a noun, the phrase the organism's trying to metabolize in A is unidiomatic because trying is used as the object of organism's. In B, trying that it metabolize is ungrammatical. The noun attempt could follow organism's; also, it would parallel the noun enzymes, and parallelism is needed here because the sentence uses the linking verb are to equate enzymes and attempt. In C and D, however, attempt to try is redundant. Choice E, which says attempt to metabolize, is best. The phrase the chemical irritant is also the most concise and precise conclusion for the sentence because it clearly refers to the dioxin mentioned earlier.这是OG里的答案解释，可以参考一下。我对这句话的大意翻译为：

事实上，在各种物种的所有组织中，dioxin导致一种酶的产生，这种酶是有机物试图用于产生代谢，呈现无害化学刺激的。欢迎大家指正！