A- Incorrect, this option doesn't explain the significant decline from the previous one year to the next
B- Incorrect, this option strengthens the explanation given by the epidemiologists
C- Incorrect, we are concerned with the decline from the previous one year to the next not only the last year. This option could weaken the argument if the scope was only Last year.
D- Correct, if neighboring cities that are located farther from the closed coal plant did not observe decreases in turbeculosis diagnoses this year as compared to last year, hence the explanation given by the epidemiologists falls apart considering the fact that it's not the closing of the coal plant who is responsible of the decrease in contraction of the disease.
E- Incorrect, clearly OUT OF SCOPE
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KUDOS is the good manner to help the entire community.

IMO A
A. Due to a new medical technique introduced into the city this year, many people who would have been
diagnosed with tuberculosis are now correctly diagnosed with emphysema.

This gives alternate reason for decrease in cases of TB. Due to incorrect diagnosis, the number of TB cases was high. But, now with new technique,many cases are correctly diagnosed.

D must be the answer.

Please see the rules for posting in verbal section

rules-for-posting-in-verbal-gmat-forum-134642.html

Also add OA

Thank you.

regards
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KUDOS is the good manner to help the entire community.

it's really painful to wait for the OA when everyone seems attached to the choice he made especially when the source could be not official one ..

GC14 please add OA and source please
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KUDOS is the good manner to help the entire community.

Epidemiologists conclusion is that the closing of the coal plant is responsible for significant reduction is the no of people diagnosed with tuberculosis.

Prethinking :- we have to find some other factor that is responsible for reduction

POE :-
Option A :- Correct, this option states that closing of coal factory has not reduced the number.
Option B :- The reason for the closing of coal factory is out of scope
Option C :- This option although provide reasons for reduction in no of persons diagnosed, does not weaken the conclusion. this option can be considered as an additional factor along with the closing of factory. Hence this is not the correct answer.
Option D :- talks about cities that are farther from factory, so out of scope
Option E :- talks about other smaller plants still in operation, so out of scope.

IMO :- A

Why not E ??

zthere are other coal factories in town which means that coal factories themselves are not the cause od the desease...

Since there was some confusion about the various options, let's discuss the question in detail.

Argument:
The number of people diagnosed with tuberculosis decreased significantly this year.
Epidemiologists attributed this decline to the closing of a coal plant on the outskirts of the city. - we need to weaken this
Coal fumes can cause acute lung inflammation that can lead to the contraction of tuberculosis.

We need to look for some other reason for the decline in the number of tuberculosis diagnoses or something that tells us why closing of the coal plant may not be responsible for the decrease.

A. Due to a new medical technique introduced into the city this year, many people who would have been diagnosed with tuberculosis are now correctly diagnosed with emphysema.
This could certainly be a reason for the decreased number of tuberculosis diagnoses. It says that the number of tuberculosis diagnoses in the previous year was exaggerated - in this year the people who had emphysema were correctly diagnosed and were not clubbed with people who had tuberculosis. This could be a reason (other than the closing of the coal plant) for the decline in the number of tuberculosis diagnoses.

B. The coal plant near the city closed, at least in part, because it was found to be polluting the air with particles that are dangerous when breathed.
We already know this from the premises. It just tells us why it was closed. It anything, it strengthens the epidemiologists' explanation for the decrease in tuberculosis diagnoses

C. Of those diagnosed with tuberculosis last year, a large number received immediate medical treatment that halted the progression of the disease.
The treatment of those diagnosed last year is out of scope here. We are looking at the number of people who got diagnosed this year.

D. Neighboring cities that are located farther from the closed coal plant did not observe decreases in tuberculosis diagnoses this year as compared to last year.
This option also strengthens the epidemiologists' explanation for the decrease in tuberculosis diagnoses a little. It explains that cities far from the coal plant have not experienced this decrease so it is more probable now that the closing of the coal plant has resulted in the decrease of the number of tuberculosis cases.

E. Although one large coal plant closed, there are still several smaller coal plants in operation within the borders of the city.
This is out of scope too. Even if there are other harmful agents, the closing down of one major harmful agent could certainly be responsible for the decrease in the number of cases.

Answer (A)
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Karishma
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