Sentence Correction

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

OA: E

Sorry, I know my question is a little silly, but what's the meaning of "that are the organism's attempt to metabolize, or render harmless, the chemical irritant"part?
Is it trying to say "doxin triggers certain enzyme production, this production is the organism's attempt to metabolize the doxin?" I think this is a little wierd.
Please help explain that~ Thank you!

The Flow : Irritant enters the body - Body produces Dioxin - Dioxin induces enzymes.

Production of these Enzymes - Organism's attempt to metabolize, or render harmless, the chemical irritant