CAT Critical Reasoning Practice question with Solution 64

The inference comes right out of the first sentence: If the only way a bookstore can profitably sell books at below market prices is to get the books at a discount from publishers, then it certainly must be true that a bookstore that is profitably selling books at below market prices is getting discounts from publishers.

(A) and (B) both confuse necessity with sufficiency: For (A), it’s necessary to receive discounts to sell at below-market prices, but it’s not a guarantee. As for (B), a high volume relies on either exclusive access or a large specialized market (a necessary condition), but neither of these things necessarily guarantees (i.e., is sufficient) a high sales volume.

(D) The bookstore in this choice (one that doesn’t sell books at below-market prices) is entirely outside of the scope of the argument, so nothing can be inferred about it.

(E) No; it's quite possible that a bookstore with exclusive access to a large specialized market that also caters to mass tastes will be able to sell books at a discount.