Prateek176 wrote:
How can option C be the OA?? It says that "People with respiratory illnesses are generally told by doctors that they must limit or cease their aerobic exercise routines". As per our conclusion, we are concerned with prevention of respiratory illnesses.
Also many people in the previous posts are inclined towards D. IMO D is incorrect because even though Recent studies have debunked the conventional wisdom that aerobic exercise is an effective preventer of heart disease, aerobic exercises may still be a preventor of respiratory diseases.
Experts please comment
To answer this question, we need a choice that weakens the support for the conclusion. So, one thing that we have to do is to identify exactly what the conclusion is.
Conclusion: Regular aerobic exercise can be helpful in preventing respiratory illness.
We also have to determine how this conclusion is supported. In this case the support for the conclusion is a correlation. The correlation is between exercise and relatively low incidence of respiratory illness. From this correlation, the author concludes that exercise prevents respiratory illness.
However, this correlation could result in multiple ways.
- Exercise prevents respiratory illness.
- Respiratory illness causes people not to exercise.
- People who exercise are less likely to smoke or do other things that cause respiratory illness. So, there is a third factor, healthier living habits, that is associated with both exercise and lower incidence of respiratory illness.
- There could be no clear connection between exercise and lower incidence of respiratory illness. They may just happen to be correlated without there being a known reason for the correlation.
The conclusion is based on the conception that the first - exercise prevents illness - is the reason for the correlation. Information indicating that one of the other relationships is the actual reason would weaken the support for the conclusion.
OK, now let's consider answer choice (D).
D. Recent studies have debunked the conventional wisdom that aerobic exercise is an effective preventer of heart disease.
This choice doesn't give us much useful information. The conclusion is that exercise prevents respiratory illness. The fact that it does not prevent heart disease (a suspect "fact" by the way), does not indicate that it does not prevent respiratory illness. In fact, the argument provides some evidence, the correlation, that exercise does prevent respiratory illness, and this choice does not weaken the support that that evidence provides for the conclusion. I mean, MAYBE we could make the case that, if aerobic exercise does not prevent heart disease, we should question the truth of the idea that it prevents respiratory illness, but really, that case is not very strong.
Now, let's consider choice (C).
C. People with respiratory illnesses are generally told by doctors that they must limit or cease their aerobic exercise routines.
This is interesting, because it provides an alternative explanation for the correlation. This choice gives us reason to believe that, rather than exercise prevents respiratory illness, respiratory illness causes people not to exercise. By providing a clear reason to believe that the reason for the correlation is different from the conception upon which the conclusion of the argument is based, this choice provides a reason to believe that the conclusion may be incorrect.
Thus, choice (C) definitely weakens the argument and is, therefore, a solid OA.
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