KAPLAN OFFICIAL EXPLANATION
(E) Logical FlawWhen looking for your pre-phrased answer in a Flaw
question, stay flexible—the right answer may phrase
that answer in more abstract terms.
Good news from this doctor: being slightly overweight
is enough to guarantee your health. How does she
know? Apparently, research shows that those who are
slightly overweight are healthier than those who are
considerably underweight. But that evidence doesn’t
establish the doctor’s conclusion because those
“considerably underweight” people may be quite
unhealthy. The slightly overweight people might be
comparatively healthier than the considerably
underweight, without being affirmatively healthy. In
other words, the doctor uses evidence of relative
health to establish a claim of absolute health, which is
what (E) says. Don’t worry if you were initially thrown
off by the wording of (E). It encapsulates the problem
with the doctor’s argument, so it has to be right, even
if it uses language you didn’t pre-phrase.
(A) The doctor doesn’t ignore any medical opinions.
She actually cites them at the beginning of the
argument.
(B) The doctor doesn’t need to provide a specific
definition of “healthy” in order to make her argument.
The issue is that “healthier than other people” doesn’t
necessarily mean “healthy.”
(C) There is no language in the argument to indicate
that the doctor is not taking this into account. She
never argues, for example, that there is a universal
threshold for classification as “overweight” or
“underweight.”
(D) The doctor never argues that lacking weight
suffices to make one unhealthy. Rather, she argues
that having a few extra pounds suffices to make one
healthy.