A porcupine’s quills, unlike a hedgehog, are neither poisonous nor easy to remove from the body of an adult animal.
(A) unlike a hedgehog
(B) in contrast to a hedgehog
(C) unlike those of a hedgehog
(D) contrasting with that of a hedgehog
(E) contrasting with a hedgehog
Scroll down for the answer.
The original version of the sentence incorrectly compares a porcupine’s quills (things) to an adult hedgehog (animal). (B) and (E) contain the same error. (D) is incorrect because the idiomatic expression is “in contrast to.” This answer is also incorrect because that, the pronoun used to replace quills, is singular whereas quills is plural. That leaves (C), which correctly and idiomatically compares quills to quills (those of = the quills of). Note that on the GMAT, correctly formed comparisons tend to use like/unlike, whereas incorrect answers involve a variety of wordier options.