Logical reasoning PrepTest 142 · Section 1 · Question 23

Incorrect. If anything, this answer undermines the dominant view by suggesting something present in oil isn't present in what that view says formed into oil.

Incorrect. While the timeline is important in this argument, without dating the oil's formation relative to these organisms, this answer has an unclear effect on the argument.

Incorrect. There very well may have been millions of years for that to happen! While the timeline is important to this question, enough of it isn't established to know whether there was time for the plants/animals to become oil.

Correct. Argument or Facts:
Argument

Valid or Flawed:
Flawed

Question Type:
Weaken

Stimulus Summary:
Dominant view Ð Oil formed from plant/animal remains
New view Ð Oil formed from deep carbon deposits from when the Earth formed
Rebuttal to new view Ð Oil has biomarkers, which indicate living organisms
Conclusion Ð New view is wrong

Answer Anticipation:
This stimulus is interesting in that it pivots to a view that challenges a commonly held viewpoint, only it ultimately disagrees with that view instead of having it serve as the main point!

As such, this Weaken question is asking us to weaken the attack on the new theory—that oil formed from deep carbon deposits. The Geologist attacked this argument by noting the presence of biomarkers in the oil—molecules that indicate the presence of a living organism. That would certainly seem to suggest that the oil formed from living remains rather than deep carbon deposits from before things lived on Earth.

Since the Geologist's argument relies on these biomarkers to undermine the conclusion that deep carbon deposits formed into oil, anything that calls into question whether this evidence is strong evidence will weaken the conclusion. For example, anything that suggests the biomarkers are more recent than the oil formed would suggest that they don't prove a plant/animal basis for the oil.

And one last note—the author's conclusion here is specifically about the deep carbon theory being wrong, not about the dominant view being correct. As such, we're unlikely to see a correct answer that bolsters the dominant view.

Answer Explanation:
This answer suggests an alternative source of biomarkers to plants/animals that could coexist with the deep carbon deposit theory. If the biomarkers are from bacteria thriving deep in the Earth's crust, then the biomarkers could come from that bacteria and not the remains of plants/animals. The biomarkers are no longer great evidence against the deep carbon deposit theory, and so this answer weakens their use to rebut that theory.

Key Takeaway:
When there are multiple theories discussed in a stimulus, be sure to track what they say, who agrees with them, and what evidence is used in support of them and to undermine them. A lot of the difficulty in these questions is bookkeeping—keeping all the information straight!

Incorrect. These carbon deposits would need to be distinct from the ones from the Earth's formation. There's also no indication that these carbon deposits are potential sources of oil. So this answer is out of scope.