Critical Reasoning

I know that this has already been brought up a couple of times but I would like to revive this topic because of several issues with the construction:

Market Analyst: Recent research confirms that the main cause of bad breath is bacteria build-up on the tongue. The research also concludes that tongue scrapers, when used properly, can eliminate up to 40% of the bacteria from the tongue. As the effectiveness of tongue scrapers becomes more widely known, the market for less effective breath freshening products, such as mints, gums, and sprays, will decline significantly.

Which of the following provides the best evidence that the analyst's argument is flawed?

A: Some breath freshening products are advertised to eliminate up to 30% of the bacteria from the tongue.
B: Tongue scrapers have already been on the market for a number of years.
C: Many dentists recommend regular flossing, and not the use of the tongue scraper, to combat bad breath.
D: A recent survey shows that 94% of those who regularly purchase breath freshening products are aware of the effectiveness of the tongue scraper.
E: Some people buy breath freshening products for reasons other than to fight bad breath.

OA: D

David@GMATPrepNow wrote:Hi francoimps,

The flaw in the argument hinges on a implied causal relationship between people knowing certain information, and changing their behaviour. Specifically, the argument is that if people know that tongue scraping is a good way to eliminate bad breath, they will stop purchasing other products (mints, gums, and sprays) for eliminating bad breath.

Answer D directly addresses the flaw:

A recent survey shows that 94% of those who regularly purchase breath freshening products are aware of the effectiveness of the tongue scraper.

Answer D undermines the notion of a causal relationship between knowledge and behaviour change. It says the opposite: that most people who buy other products DO KNOW that tongue scraping is a good way to eliminate bad breath (but they buy the other products anyway).

Answer E is more of a follow up and counterpoint to answer D than it is evidence of a flaw in the passage. Maybe those people like to buy products that are green, for example. That "fact" does not point out a flaw in the argument, it just suggests a reason why people buy the other products.

Hi David,

My line of thinking below still prevents me from agreeing with D:

Conclusion of the argument: As the effectiveness of tongue scrapers becomes more widely known, the market for less effective breath freshening products, such as mints, gums, and sprays, will decline significantly.

Answer choice D: A recent survey shows that 94% of those who regularly purchase breath freshening products are aware of the effectiveness of the tongue scraper.

What if it were the case that because the effectiveness of tongue scrapers becomes more widely known, then NEW ENTRANTS to the market would cause a decrease in the market for less effective breath freshening products indirectly? New entrants could drive up the market share of tongue scrapers significantly such that even if the current number of consumers of other breath freshening products remains the same (or even increases), its current market share would decline due to the impact of the new entrants increasing the share of tongue scrapers. Again, the result of these new entrants are due to the effectiveness of tongue scrapers which has becomes more widely known.

Moreover, answer choice D states that the respondents of the survey are those who are already aware of the effectiveness of the scraper. This fact can be directly countered by the conclusion of the argument: "As the effectiveness of tongue scrapers becomes more widely known..."

Answer Choice E on the other hand would provide a more reasonable weakening scenario: "Some people buy breath freshening products for reasons other than to fight bad breath."

This answer choice provides an alternative cause for the consumption of breath freshening products. (i.e., Instead of X-->Y, "Z" -->Y). This would imply that even if people do become more aware of the effectiveness of the product, (both current market and potential market), then the reason for increased effectivity would not necessarily ignite a decrease in the market for other products (i.e., because there is another cause (Z) for purchasing them).

Question stem- "As the effectiveness of tongue scrapers becomes more widely known"

D-A recent survey shows that 94% of those who regularly purchase breath freshening products are aware of the effectiveness of the tongue scraper.

94% of people buying breath freshening product are already aware of the effectiveness of tongue cleaner