Most geologists believe oil results from chemical transformations of hydrocarbons derived from organisms buried under ancient seas. Suppose, instead, ...
GMAT Critical Reasoning : (CR) Questions
Most geologists believe oil results from chemical transformations of hydrocarbons derived from organisms buried under ancient seas. Suppose, instead, that oil actually results from bacterial action on other complex hydrocarbons that are trapped within the Earth. As is well known, the volume of these hydrocarbons exceeds that of buried organisms. Therefore, our oil reserves would be greater than most geologists believe.
Which of the following, if true, gives the strongest support to the argument above about our oil reserves?
Passage Analysis:
| Text from Passage | Analysis |
| Most geologists believe oil results from chemical transformations of hydrocarbons derived from organisms buried under ancient seas. |
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| Suppose, instead, that oil actually results from bacterial action on other complex hydrocarbons that are trapped within the Earth. |
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| As is well known, the volume of these hydrocarbons exceeds that of buried organisms. |
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| Therefore, our oil reserves would be greater than most geologists believe. |
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Argument Flow:
The argument starts by presenting the standard geological view, then introduces an alternative theory about oil formation. It supports this alternative with a key fact about the greater volume of source materials, then concludes that this would mean larger oil reserves.
Main Conclusion:
Our oil reserves would be greater than most geologists believe.
Logical Structure:
The argument uses a simple if-then structure: IF oil comes from bacterial action on trapped hydrocarbons (alternative theory) AND there are more trapped hydrocarbons than buried organisms (established fact), THEN we'd have more oil reserves than currently believed. The logic depends on the idea that more source material equals more final product.
Prethinking:
Question type:
Strengthen - We need to find information that makes the conclusion (oil reserves would be greater than geologists believe) more believable
Precision of Claims
The argument makes quantity claims about hydrocarbon volumes and activity claims about bacterial processes converting hydrocarbons to oil
Strategy
To strengthen this argument, we need evidence that supports either: (1) the bacterial theory is actually viable/true, (2) the trapped hydrocarbons can actually be converted to oil efficiently, or (3) the process would indeed result in more accessible oil reserves than the traditional theory predicts
This choice tells us that most geologists are optimistic about oil reserves, but this doesn't help strengthen the argument about the bacterial theory leading to greater reserves. Even if geologists are already optimistic, the argument could still be correct that reserves would be even greater under the bacterial theory. This choice is irrelevant to evaluating whether the bacterial theory would actually result in more oil.
This choice about geologists performing accurate chemical analyses on existing reserves doesn't strengthen the argument. The argument isn't questioning the accuracy of current reserve estimates, but rather proposing that a different formation process (bacterial vs. chemical transformation) would lead to different reserve quantities. Past analytical accuracy doesn't tell us anything about whether the bacterial theory would yield more oil.
This choice about ancient seas being buried where fossils are abundant actually supports the mainstream geological view rather than the alternative bacterial theory. If anything, this might weaken the argument by providing evidence for the traditional theory about oil formation from buried sea organisms.
This choice suggests that bacteria found in oil reserves might just be surface contamination, which would actually weaken the bacterial theory rather than strengthen it. If the bacteria aren't naturally occurring in the oil formation process, this undermines the alternative theory the argument is promoting.
This is the correct answer because it addresses the critical gap in the argument's logic. The argument assumes that more source material (trapped hydrocarbons vs. buried organisms) automatically means more oil reserves. However, this only works if the conversion processes are similarly efficient. By telling us that both chemical transformations and bacterial action reduce hydrocarbon volume by roughly the same proportion, we can confidently conclude that starting with more source material would indeed result in proportionally more oil reserves. This directly strengthens the conclusion.