OG 10 -6 求助。。

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

答案是e，句子前一部分我能理解，但是我不懂the
   chemical irritant的用法，它放在句尾是个啥意思啊。。。

谢谢！

我觉得the chemical是dioxin的同位语，irritant修饰the chemical,省了that is