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- Fri Jul 29, 2016 11:55 am
#27573
Complete Question Explanation
Weaken—CE. The correct answer choice is (D)
In this example, the author discusses a layer of iridium that has been presented as evidence of a meteorite collision with Earth, based on the fact that such a collision could cause a cloud of iridium dust that would eventually settle and become a layer of rock.
The question that follows asks for the choice that would weaken the assertion that the layer of iridium rock supports the meteorite theory. To weaken the causal argument advanced by the author, a good start is to look for alternative causes of the iridium rock layer.
Answer choice (A): A decrease in the earth’s temperature is not mentioned in the stimulus as does not weaken the claim that the iridium layer can support the meteorite hypothesis.
Answer choice (B): How long the rock took to harden is irrelevant to this discussion, which only concerns how it was formed, not when it was formed.
Answer choice (C): This choice has nothing to do with the author’s discussion and does not weaken the causal hypothesis presented in the stimulus.
Answer choice (D): This is the correct answer choice, as it provides an alternative cause of the layer of iridium: if volcanic activity could have led to the same result, this weakens the causal hypothesis presented by the author.
Answer choice (E): This choice cannot be the right answer to this Weaken question, because this one would strengthen the assertion that a meteorite collision took place.
Weaken—CE. The correct answer choice is (D)
In this example, the author discusses a layer of iridium that has been presented as evidence of a meteorite collision with Earth, based on the fact that such a collision could cause a cloud of iridium dust that would eventually settle and become a layer of rock.
The question that follows asks for the choice that would weaken the assertion that the layer of iridium rock supports the meteorite theory. To weaken the causal argument advanced by the author, a good start is to look for alternative causes of the iridium rock layer.
Answer choice (A): A decrease in the earth’s temperature is not mentioned in the stimulus as does not weaken the claim that the iridium layer can support the meteorite hypothesis.
Answer choice (B): How long the rock took to harden is irrelevant to this discussion, which only concerns how it was formed, not when it was formed.
Answer choice (C): This choice has nothing to do with the author’s discussion and does not weaken the causal hypothesis presented in the stimulus.
Answer choice (D): This is the correct answer choice, as it provides an alternative cause of the layer of iridium: if volcanic activity could have led to the same result, this weakens the causal hypothesis presented by the author.
Answer choice (E): This choice cannot be the right answer to this Weaken question, because this one would strengthen the assertion that a meteorite collision took place.