Line Although genetic mutations in bacteria and viruses
can lead to epidemics, some epidemics are caused
by bacteria and viruses that have undergone no
significant genetic change. In analyzing the latter,
(5) scientists have discovered the importance of social
and ecological factors to epidemics. Poliomyelitis,
for example, emerged as an epidemic in the United
States in the twentieth century; by then , modern
sanitation was able to delay exposure to polio until
(10) adolescenceor adulthood, at which time polio
infection produced paralysis. Previously, infection
had occurred during infancy, when it typically
provided lifelong immunity without paralysis. Thus,
the hygiene that helped prevent typhoid epidemics
(15) indirectly fostered a paralytic polio epidemic.
Another example is Lyme disease, which is caused
by bacteria that are transmitted by deer ticks. It
occurred only sporadically during the late
nineteenth century but has recently become
(20) prevalent in parts of the United States, largely due
to an increase in the deerpopulation that occurred
simultaneously with the growth of the suburbs and
increased outdoor recreationa l activities in the
deer's habitat. Similarly, an outbreak of dengue
(25) hemorrhagic fever became an epidemic inAsia in
the 1950s because of ecological changes that
caused Aedes aegypti, the mosquito that transmits
the dengue virus, to proliferate. The stage is now
set in the United States for a dengue epidemic
(30) because of the inadvertent introduction and wide
dissemination of another mosquito, Aedes albopictus.
The passage suggests that a lack of modern sanitation would make which of the following most
likely to occur?
(A) An outbreak of Lyme disease
(8) An outbreak of dengue hemorrhagic fever
(C) An epidemic of typhoid
(D) An epidemic of paralytic polio among infants
(E) An epidemic of paralytic polio among adolescents and adults
Correct answer is : C
My question is, if the option C were not in the answer option and Option D were An epidemic of polio among infants, then option D would had been right?
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Genetic Mutation
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David@GMATPrepNow
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Hi chetan86,
Answer D is tempting, but it is not strictly correct - not even if answer C was not part of the answer set.
We're told that "modern sanitation was able to delay exposure to polio," which directly implies that the lack of modern sanitation would not delay exposure, meaning that infants would be exposed to polio. But exposure does not necessarily result in an epidemic of polio. In fact, the passage tells us that it is "better" to be exposed to polio as an infant than as an adult, because the symptoms of the infection are less serious. Answer D is not correct.
Be careful to avoid the temptation of saying "this answer would be more correct if that answer was not present." On the exam, there is only one correct answer. If you are tempted to think there are a couple (or more) correct answers, circle them and come back to them later when you have had time to work on some other questions first. With fresh perspective, you will be more likely to see the one correct answer, rather than several "could be if..." answer.
Answer D is tempting, but it is not strictly correct - not even if answer C was not part of the answer set.
We're told that "modern sanitation was able to delay exposure to polio," which directly implies that the lack of modern sanitation would not delay exposure, meaning that infants would be exposed to polio. But exposure does not necessarily result in an epidemic of polio. In fact, the passage tells us that it is "better" to be exposed to polio as an infant than as an adult, because the symptoms of the infection are less serious. Answer D is not correct.
Be careful to avoid the temptation of saying "this answer would be more correct if that answer was not present." On the exam, there is only one correct answer. If you are tempted to think there are a couple (or more) correct answers, circle them and come back to them later when you have had time to work on some other questions first. With fresh perspective, you will be more likely to see the one correct answer, rather than several "could be if..." answer.
