Asthma, a chronic breathing disorder, is significantly more common today among adult competitive swimmers than it is among competitive athletes...
GMAT Critical Reasoning : (CR) Questions
Asthma, a chronic breathing disorder, is significantly more common today among adult competitive swimmers than it is among competitive athletes who specialize in other sports. Although chlorine is now known to be a lung irritant and swimming pool water is generally chlorinated, it would be rash to assume that frequent exposure to chlorine is the explanation of the high incidence of asthma among these swimmers, since ______________.
Which of the following most logically completes the argument given?
Passage Analysis:
| Text from Passage | Analysis |
| Asthma, a chronic breathing disorder, is significantly more common today among adult competitive swimmers than it is among competitive athletes who specialize in other sports. |
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| Although chlorine is now known to be a lung irritant and swimming pool water is generally chlorinated |
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| it would be rash to assume that frequent exposure to chlorine is the explanation of the high incidence of asthma among these swimmers |
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| since _____ |
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Argument Flow:
The argument starts with a surprising observation (swimmers get asthma more than other athletes), then presents what looks like an obvious explanation (chlorine in pools hurts lungs), but then warns us not to jump to that conclusion. The flow creates tension by setting up an apparent cause-effect relationship and then questioning it.
Main Conclusion:
We shouldn't assume that chlorine exposure explains why swimmers get asthma more often than other athletes.
Logical Structure:
This is an incomplete argument that's building toward showing why the obvious explanation (chlorine causes swimmer asthma) might be wrong. The structure is: [Observation] + [Apparent Cause] + [Warning Against Assuming Causation] + [Missing Evidence]. We need to find the missing piece that gives us a good reason to doubt the chlorine explanation.
Prethinking:
Question type:
Logically Completes - We need to find a statement that logically supports why it would be rash to assume chlorine exposure explains the high asthma rates among swimmers
Precision of Claims
The passage makes specific claims about frequency (asthma is significantly more common among swimmers), causation (chlorine is a lung irritant), and scope (adult competitive swimmers vs other competitive athletes)
Strategy
Since the argument warns against assuming chlorine causes swimmers' asthma, we need to find reasons that challenge this causal connection. The completion should provide alternative explanations, point out flaws in the reasoning, or show why the chlorine theory doesn't hold up. We're looking for information that makes the chlorine explanation less convincing or shows there are other factors at play.
This tells us that having asthma doesn't make someone more or less likely to become a competitive athlete in general. While this is interesting background information, it doesn't specifically help explain why we shouldn't blame chlorine for swimmers' higher asthma rates. It doesn't provide an alternative explanation or challenge the chlorine theory directly.
This states that non-swimming athletes rarely get exposed to chlorine. Actually, this would SUPPORT the chlorine theory rather than challenge it - if other athletes don't get chlorine exposure and swimmers do, and swimmers have more asthma, that would make chlorine look more suspicious as the cause. This goes in the wrong direction for completing our argument.
This tells us athletes overall have less asthma than non-athletes. This is general information about athletes as a group, but it doesn't address the specific question of why swimmers have more asthma than OTHER athletes, nor does it give us reason to doubt the chlorine explanation. It's talking about a different comparison entirely.
This reveals that doctors used to specifically recommend swimming to kids who ALREADY had asthma, thinking it might help their symptoms. This is a game-changer! It provides a compelling alternative explanation for why adult competitive swimmers have higher asthma rates - not because swimming/chlorine caused their asthma, but because people with asthma were specifically directed toward swimming as children. This creates selection bias that could fully explain the observation without blaming chlorine exposure.
This suggests that strenuous activities like competitive athletics help diagnose previously unknown asthma cases. While this could explain why athletes in general might show higher diagnosed asthma rates, it doesn't specifically explain why SWIMMERS have higher rates than OTHER competitive athletes, since all competitive athletes engage in strenuous activity. It doesn't challenge the chlorine theory effectively.