an CR from Gmatclub

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an CR from Gmatclub

by diebeatsthegmat » Wed Oct 27, 2010 11:30 pm
Brain scans of people exposed to certain neurotoxins reveal brain damage identical to that found in people suffering from Parkinson's disease. This fact shows not only that these neurotoxins cause this type of brain damage, but also that the brain damage itself causes Parkinson's disease. Thus brain scans can be used to determine who is likely to develop Parkinson's disease.

The argument contains which one of the following reasoning errors?
(A) It fails to establish that other methods that can be used to diagnose Parkinson's disease are less accurate than brain scans.
(B) It overestimates the importance of early diagnosis in determining appropriate treatments for people suffering from Parkinson's disease.
(C) It mistakes a correlation between the type of brain damage described and Parkinson's disease for a causal relation between the two.
(D) It assumes that people would want to know as early as possible whether they were likely to develop Parkinson's disease.
(E) It neglects to specify how the information provided by brain scans could be used either in treating Parkinson's disease or in monitoring the progression of the disease.

[spoiler]hi, guysm can you please explain me why the answer is B and not C? i chose C and the website i watched this question said the answer is B... B says about treatment while i think treatment is out of scope. the CR all says about the cause of P... so if its B the answer, i dont understand....[/spoiler]

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by yuliawati » Wed Oct 27, 2010 11:47 pm
This is one of 1000 CR questions.

I also picked C. I dont understand why the OA is B.
The conclusion is "brain scan CAN be used to determine who is likely to develop parkinson disease". So, I think B is out of scope.

Need the explanation from the expert T_T

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by Testluv » Thu Oct 28, 2010 2:13 am
Choice C is definitely correct. There are two flaws in this argument: a) the author assumes that the because (certain) neurotoxin exposure and Parkinson's results in the same type of brain damage that these neurotoxins cause the type of brain damage characteristic of Parkinson's (when it could be that something else causes that type of brain damage in people suffering from Parkinson's; and b) he also assumes that the correlation between brain damage and Parkinson's means there is a causal relation between the two (when in fact they can both be the result of some third factor).

Choice B is irrelevant. The author argues that brain scans can be used to predict who will get Parkinson's. While this would be an early diagnosis, the importance of early diagnosis is outside the scope. And, clearly, "treatments" are outside the scope.
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by diebeatsthegmat » Thu Oct 28, 2010 11:12 am
Testluv wrote:Choice C is definitely correct. There are two flaws in this argument: a) the author assumes that the because (certain) neurotoxin exposure and Parkinson's results in the same type of brain damage that these neurotoxins cause the type of brain damage characteristic of Parkinson's (when it could be that something else causes that type of brain damage in people suffering from Parkinson's; and b) he also assumes that the correlation between brain damage and Parkinson's means there is a causal relation between the two (when in fact they can both be the result of some third factor).

Choice B is irrelevant. The author argues that brain scans can be used to predict who will get Parkinson's. While this would be an early diagnosis, the importance of early diagnosis is outside the scope. And, clearly, "treatments" are outside the scope.
yes, i also think B is irrelevant... thank you a lot, testluv