According to a study of more than 50,000 Norwegian smokers, reducing nicotine intake, even by up to 50 percent, does not provide significant health benefits. The mortality rate for those who cut back was not lower than that for heavier smokers, nor did the “reducers” fare any better when it came to cardiovascular disease.

Which of the following, if true, most seriously jeopardizes the findings of the study described above?
A) The majority of study participants minimized their withdrawal symptoms through the use of nicotine patches and chewing gum.
B) Many of the study’s participants periodically dined in restaurants in which smoking was permitted.
C) The study’s participants started smoking at different ages and had varied initial nicotine intake.
D) Quitting smoking entirely results in a marked reduction in the ill effects of smoking.
E) Men and women who smoked pipes and cigars were excluded from the study.

Answer is A.
I don't understand why its A per the explanation:

(A) CORRECT. This answer choice indicates that most study participants did not actually reduce their nicotine intake; instead, they simply received nicotine from different sources. Since the data on which the conclusion is based is not reliable, the conclusion is undermined.

Isn't A just saying, that for the people in the study, they help control withdraw symptoms via patches and gums. This has no relevance to to jeoparidizing the study. I thought A was simply irrelevant. Can someone help explain?

Well, A is the most obvious answer to this question. This can be answered in 2 ways, eliminating all the other answer choices, this is simple because the other options doesn't relate to the question asked. They are asking for statement jeopardizes the *findings* not the conclusion. It means, though they reduced the nicotine intake by 50%,they used nicotine patches and cheewing gums, whcih reduces the symptoms but maintains the same effects on their health. Here, the finding s that 'According to a study of more than 50,000 Norwegian smokers, reducing nicotine intake, even by up to 50 percent, does not provide significant health benefits', thus statement A clearly endangers the finding.

hope it helps. suggestions are welcomed!

Well, A is the most obvious answer to this question. This can be answered in 2 ways, eliminating all the other answer choices, this is simple because the other options doesn't relate to the question asked. They are asking for statement jeopardizes the *findings* not the conclusion. It means, though they reduced the nicotine intake by 50%,they used nicotine patches and cheewing gums, whcih reduces the symptoms but maintains the same effects on their health. Here, the finding s that 'According to a study of more than 50,000 Norwegian smokers, reducing nicotine intake, even by up to 50 percent, does not provide significant health benefits', thus statement A clearly endangers the finding.

hope it helps. suggestions are welcomed!

I'm still not understanding your reasoning.
Isn't A just talking about reducing the side affect? A is not discussing the actual nicotine intake of those participants. Can you or anyone explain your thought process on this questions. thanks

On reviewing the question, we agree -- it's flawed. The question stem did not make clear that the study participants reduced their nicotine intake from smoking by up to 50%. We have changed the question accordingly. We have also clarified the claim of the study sponsors (i.e., that "reducing nicotine intake does not improve one's health"), which was previously only implied. Finally, we added the point that the skin patches & chewing gum provide nicotine to the body.

I hope this tightens up the logic! Thanks for your alert.