Explanation
The question asks us to identify a potential flaw in the reasoning presented in a survey about the effects of aerobic exercise on lung disease risk.
A. The argument does not address anecdotal evidence, so criticizing it for ignoring anecdotal evidence is not pertinent to the given reasoning.
B. The argument does not mention reliance on surveys from only one medical journal; it refers to "surveys," suggesting multiple sources.
C. (Correct Response) The argument makes a conclusion about causation based on observed correlation. It states that because a correlation between aerobic exercise frequency and lower risk of lung disease was found, aerobic exercise must have a significant beneficial effect, which assumes causality from correlation without further justification.
D. The argument does not make any claims about the overall health of people without lung disease or their exercise habits, so it does not presume anyone without lung disease is in good health.
E. While this is a valid consideration, the argument's claim is about the effect of frequent aerobic exercise, not the effect of infrequent exercise, so this does not directly question the argument's reasoning.
The reasoning is questionable because it concludes that aerobic exercise causes a reduction in lung disease risk solely based on a correlation, which is a common logical fallacy. Thus, option C identifies the flaw in the argument.