Quote:
The number of people diagnosed with dengue fever (which is contracted from the bite of an infected mosquito) in North India this year is twice the number diagnosed last year. The authorities have concluded that measures to control the mosquito population have failed in this region.
All of the following, if true, would cast doubt on the authorities conclusion except
A. more cases are now reported because of increases in administrative efficiency
B. a very high proportion of the cases were in people who had recently returned from neighboring countries
C. an effective diagnostic test was introduced about nine months ago
D. the disease is prevalent only in some industrialized areas which have shown a dramatic increase in population due to migration
E. the incidence (number of cases per thousand) of malaria, also contracted from mosquito bites, has increased
The correct answer here is
E. This is a "weaken the argument" question, but it is
also an "Except" question. What this means is that rather than looking for one option that weakens the conclusion, we're looking to eliminate 4 options that all weaken the conclusion.
A - This certainly weakens the argument. It
provides an alternative explanation for the increased number of reported cases which suggests that the methods have not failed, we just have better stats now.
OUTB - This also weakens the argument. If most or even many of the cases are from
people who were not from the region being tested, then it invalidates the conclusion that measures taken in the region didn't work.
OUTC - If a new test was introduced within the last year, it would account for differences in the number of reported cases, and therefore
provide an alternative explanation as to why the numbers didn't go down.
OUTD - This is wrong for the same reason that B is wrong. The fact that it is prevalent only in some areas does nothing to weaken the conclusion, but the point about migration is the same as in B. If the people with the disease are not from the region in which the measures were taken, we cannot say that the measures taken failed.
OUTE - Must be right by elimination. If we know that malaria has gone up as well, it certainly cannot be the case that the measures didn't fail, since it suggests that there are more of the mosquitoes now. This actually even strengthens the argument
CORRECTAlthough it didn't apply to this question, it is important to remember that a "Weaken [except] the argument" question doesn't mean that you have to strengthen the argument. It simply means that you have to "NOT weaken". For this reason, you're best off trying to eliminate the other four options that actually do weaken it.
- Matoo
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