sillyboy wrote:
Recently in our county, sales of beer have suffered a significant decline in restaurants, nightlife establishments, and retail stores. During this same time, the sheriff's office has initiated a new and well-funded campaign against the short-term dangers and long-term health risks caused by alcohol consumption. Therefore, the decrease in beer consumption has been caused by consumers' awareness of the dangers and risks of alcohol consumption.
Which of the following, if true, most seriously calls into question the explanation above?
A. On average, people in the town consume 30 percent less beer today than they did two years ago.
B. Heavy beer drinkers may have withdrawal symptoms, such as anxiety, that create other difficulties in their lives.
C. Sales of beer in different channels, such as in restaurants and in bars, have not all declined at the same rate.
D. The sheriff's campaign has been negative in tone and has largely relied on local TV advertising employing scare tactics.
E. Although beer consumption has without a doubt decreased, wine consumption in the town has significantly increased.
Source: GmatFree
OFFICIAL EXPLANATION:
Reading the question: we like the prompt, because it's not just an argument; it's a causal argument. When you spot a causal argument, you can filter for the possibility of an alternate cause. The logic of the argument is: X causes Y. An alternate possibility is that Z causes Y, so you can think of a preloaded filter for causal arguments as "looking for a Z."
Applying the filter: On to the answer choices. Choice (A) either strengthens the argument or is irrelevant. (B) gives a reason why beer drinkers might keep drinking beer, but it doesn't shed light on what has caused this particular sequence of events, so it doesn't weaken the argument and is not the correct answer. Choice (C) says that not all the rates of decline are the same. That's not so hard to believe. Bars could be down 10% and stores could be down 12% and it could all be due to the sheriff's campaign, so Choice (C) does not weaken the argument and is therefore not the correct answer. Choice (D) might reflect negatively on the sheriff, but it doesn't mean that the sheriff's campaign hasn't caused the change. Choice (E) matches our filter. The fact that wine is up gives an alternate cause for beer's decline; it's a shift in the taste of the local population. We have, in other words, "found a Z," an alternate explanation for Y. Note that the fact people are drinking more wine indicates specifically that they are not swayed by the campaign about risks of alcohol.
The correct answer is (E).