Bunuel wrote:
The Green Peas Grocery Store in the remote wealthy enclave of Luxville charges more than the Green Peas Grocery Store in Oak City charges for the same items. Clearly, on any given item, the Green Peas grocery franchise is taking advantage of its location in Luxville to reap higher profits on that item.
In evaluating the argument, it would be most useful to compare
(A) The selection of specialty items in the Oak City location with the selection of specialty items in the Luxville location
(B) The cost of transporting merchandise to the Oak City location with the comparable cost to the Luxville location
(C) The average cost of the same or comparable items at other grocery stores in Oak City with the average cost at other stores in Luxville
(D) The percent of average household income spent on groceries in Oak city with the comparable percentage in Luxville
(E) The cost of these items in Oak City and in Luxville with the cost at other Green Peas stores throughout the state.
Magoosh Official Explanation:
What we want to explain are the higher prices, for the same items, in Luxville. The argument takes a firm stand: the Luxville store is just taking advantage of its location. Implicitly, the author is saying: the Luxville store has no valid reason for charging high prices. If there were a valid reason, that would call this entire argument into question.
(B) is the credited answer. If Luxville remote, transportation to that location could be an issue, and if the additional transportation needs adds an extra cost, this would be a valid reason for charging more in the Luxville store. It would call the argument into question.
(A) is irrelevant. The comparison is between the same items in both stores, so other items, which one store has and the other doesn't have, don't affect this comparison.
(D) is a tempting answer: we already know Luxville is a wealthy enclave, so they probably spend a considerably smaller percentage of their discretionary income on groceries. It's not particular clear that know this would tell us anything we don't already know.
(C) and (E) both widen the comparison --- by comparing to other grocery franchises, or other Green Pea stores throughout the state, we probably would establish what we already suspect: the price is higher than average in the Green Peas in Luxville. The point is not merely to reinforce that but to explain it.