GMAT Sentence Correction (SC) | Re: Hundreds of species of fish generate and discharge electric

Hundreds of species of fish generate and discharge electric currents, in bursts or as steady electric fields around their bodies, using their power either to find and attack prey, to defend themselves, or also for communicating and navigating.

(A) either to find and attack prey, to defend themselves,or also for communicating andnavigating (Wrong Idiom)
(B) either for finding and attacking prey defend themselves, or for communication and navigation(Purpose so "to" required)
(C) to
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