Vavali wrote:
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.
The problem here is causation. The reasoning assumes that the fact that there is an identical brain damage, then the brain damage must be the reason for Parkinson's disease. And concludes that the brain scan could determine who is likely to develop Parkinson's disease.
The problem here is that it confuses a situation with the cause of the disease.
From the options below, only C takes care of this issue.
A. Other methods are not the scope of the passage.
B. 'Early' diagnosis not important here, treatment not important either. The role that the diagnosis plays in the treatment is not even mentioned.
C. Right on the issue.
D. Doesn't talk about what are people's wants.
E. That's not the purpose of the argument.
I think that C is the right answer.