The higher the level of certain vitamins and minerals in the bloodstream, the better a person's lung function, as measured...
GMAT Critical Reasoning : (CR) Questions
The higher the level of certain vitamins and minerals in the bloodstream, the better a person's lung function, as measured by the amount of air the person can expel in one second. The lung function of smokers is significantly worse, on average, than that of nonsmokers. Clearly, therefore, one way for smokers to improve their lung function is for them to increase their intake of food that are rich in these helpful vitamins and minerals.
Which of the following is an assumption on which the argument depends.
Passage Analysis:
| Text from Passage | Analysis |
| The higher the level of certain vitamins and minerals in the bloodstream, the better a person's lung function, as measured by the amount of air the person can expel in one second. |
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| The lung function of smokers is significantly worse, on average, than that of nonsmokers. |
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| Clearly, therefore, one way for smokers to improve their lung function is for them to increase their intake of food that are rich in these helpful vitamins and minerals. |
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Argument Flow:
The argument starts with a general scientific principle linking vitamins/minerals to lung function, then presents the specific problem that smokers have poor lung function, and finally combines these to suggest that vitamins/minerals could help smokers improve their lung function.
Main Conclusion:
Smokers can improve their lung function by increasing their intake of foods rich in certain vitamins and minerals.
Logical Structure:
The argument assumes that the general vitamin-lung function relationship applies equally to smokers, and that smokers can achieve the same benefits from vitamins as the general population, despite whatever damage smoking may have caused to their lungs.
Prethinking:
Question type:
Assumption - We need to find statements that must be true for the author's conclusion to hold. These are gaps in logic that the author is taking for granted.
Precision of Claims
The argument makes precise claims about vitamin/mineral levels affecting lung function generally, smokers having worse lung function than nonsmokers, and recommends vitamin/mineral intake as a solution for smokers specifically.
Strategy
Since this is an assumption question, we need to identify ways the conclusion could be falsified while respecting the given facts. The conclusion is that smokers can improve lung function by increasing vitamin/mineral intake. We need to find what the author must assume for this leap from general principle to specific recommendation for smokers.
This states that smokers are less likely than nonsmokers to have vitamin-rich diets. While this might explain why smokers have worse lung function, it's not an assumption the argument depends on. The argument's conclusion that smokers can improve their lung function by increasing vitamin intake would work regardless of their current dietary habits. Even if smokers already had great diets, they could still potentially benefit from increasing their vitamin intake further.
This claims that smokers with vitamin-rich diets have better lung function than nonsmokers with comparable diets. This goes too far - the argument doesn't need to assume that vitamins can make smokers' lungs better than nonsmokers'. The argument only concludes that smokers can improve their lung function, not that they can surpass nonsmokers. This assumption is stronger than what the argument requires.
This suggests that people deficient in vitamins don't typically have other health problems beyond diminished lung function. This is completely irrelevant to the argument's logic. The argument is specifically about lung function improvement for smokers through vitamin intake - other potential health problems don't affect whether this specific recommendation would work for lung function.
This states that stopping smoking won't improve lung function more than diet changes can. The argument doesn't need this assumption because it's not claiming that vitamin intake is the best or only way to improve lung function. The conclusion simply states that vitamin intake is 'one way' for smokers to improve lung function. Even if quitting smoking were more effective, vitamins could still provide some improvement.
This assumes that smoking doesn't introduce chemicals that prevent vitamins and minerals from entering the bloodstream. This is crucial because the entire argument hinges on the idea that if smokers increase their vitamin intake, they'll get higher levels of these nutrients in their bloodstream, which will then improve their lung function. If smoking blocked these nutrients from entering the bloodstream, then eating more vitamin-rich foods wouldn't lead to higher bloodstream levels, and the whole recommendation would fail. This assumption must be true for the argument to work.