<p>Organs (located in) the tail of the electric eel (enables) the animal (to produce) electricity, which it uses (in hunting) prey. (No error)</p>
<p>I thought the answer was in hunting because it has to match with the verb to produce</p>
<p>You are right about one thing, the answer is a subject-verb agreement issue. </p>
<p>The subject is Organs, which is plural and therefore requires a plural verb. Enables, is not plural, it is singular. So the answer should be enable the animal</p>