OG 12 P.88

pittlee

Sorry, I cant type Chinese coz im now using the computer of a library in Germany. I just began to prepare GMAT.
The original explaination is as below: (OG 12  age 88)

A physically active lifestyle has been shown to help increase longevity. In the Wistar region of Bellaria, the average age at
death is considerably higher than in any other part of the country. Wistar is the only mountainous part of Bellaria. A
mountainous terrain makes even such basic activities as walking relatively strenuous; it essentially imposes a physically
active lifestyle on people. Clearly, this circumstance explains the long lives of people in Wistar.
Which of the following, if true, most seriously weakens the argument?
(A) In Bellaria all medical expenses are paid by the government, so that personal income does not affect the quality of
health care a person receives.
(B) The Wistar region is one of Bellaria’s least populated regions.
(C) Many people who live in the Wistar region have moved there in middle age or upon retirement.
(D) The many opportunities for hiking, skiing, and other outdoor activities that Wistar’s mountains offer make it a favorite
destination for vacationing Bellarians.
(E) Per capita spending on recreational activities is no higher in Wistar than it is in other regions of Bellaria.

Argument Evaluation
Situation
People in one region of a country live longer than people in other areas. Th e higher average age
at time of death is attributed to the healthy lifestyle of the people in this region, where the
mountainous terrain demands a physically active life.
Reasoning
What point weakens the argument? Consider what assumption underlies the argument that the
physically active lifestyle required of living in Wistar is responsible for its residents’ relative
longevity. Th e mountainous environment necessitates lifelong levels of rigorous physical activity
that build a more robust population. What if a significant portion of the population has not
been conditioned since childhood to the demands of the terrain? It is assumed here that the
healthy lifestyle imposed by the terrain has shaped residents from birth and accounts for their
longer life span. If many residents only moved there later in life, the argument is weakened.

A Th e argument is not about the quality of health care throughout the country, but the length of the
residents’ lives in a particular region.
B Th e rate of population density does not aff ect the argument.
C Correct. Th is statement properly identifies a point that weakens the argument.
D Th e area’s popularity as a vacation destination does not affect the longevity of the local residents.
E Th e argument establishes that merely living in the region is strenuous; the spending on recreational
activities is irrelevant.
Th e correct answer is C.

The official explaination says, as I have already highlighted in green, this kind of lifestyle has shaped the residents from the birth. But there's no clue about this in the passage at all. And in contrast, as C says, ''many people moved there  in middle or upon retirement'', this assumption can exactly strengthen the argument, coz people live longer after moved there than before, this may be a result of the change of lifestyle imposed by the mountainous terrain there.
So I think the most confusing part is how could we speculate that this kind of lifestyle has shaped the residents from birth.

Can anyone help solve this problem for me???
Thank you very much!

mengchen

yeah feel confused the say way how OG explained it. But definitly disagree with you on that "people live longer after moved there than before". We couldnt get any clue from the passage.