wawatan wrote:A study of the medical records of people below the age of forty found that those whose spouses have died have a significantly lower chance of surviving to forty than do those with living spouses. This suggests that the emotional stress of being widowed severely affects widows and widowers health.

Which of the following, if true, case most doubt on this study's support for the conclusion suggested above?


B) (correct answer)
The study did not exclude deaths caused by accidents in which both members of a married couple received fatal injuries

E) Medical examinations of newly widowed people generally show them to be no less healthy than the population at large.

The bold part is the conclusion. I find that answer choice e weakens the conclusion. answer choice b weakens the premise. however the correct answer is answer b. can someone explain what is wrong with e? are we suppose to weaken the premise?

the poster above me is absolutely correct: you are trying to debunk the argument, not the factual basis of its conclusion.

by the way, this is how these 'weaken' problems work in general: statements that appear to be factual refutations of existing premises/conclusions are usually wrong answers.
the gmat is calibrating your ability to assess and critique ARGUMENTS, not factual information. therefore, weakening arguments is a two-step process:
1) identify the assumption(s) upon which the argument depends;
2) find statements among the answer choices that shoot down that/those assumption(s).

in this particular argument, the speaker advances from a simple correlation (being widowed and lower chance of survival to age 40) to a statement of causation (attributing the discrepancy to emotional stress).
whenever correlation is equated with causation, there are HUGE assumptions at work: namely, the argument's author is casting aside all other possible explanations for the correlation at hand.

that's what is happening here: the author is summarily ruling out, by fiat, any alternative explanation for widows' and widowers' increased mortality. that's a huge assumption, and one that is effectively contradicted by answer choice b (and not e).