Cigarette companies claim that manufacturing both low- and high-nicotine cigarettes allows smokers to choose how much nicotine they want. However, a recent study has shown that the levels of nicotine found in the blood of smokers who smoke one pact of cigarettes per day are identical at the end of a day's worth of smoking, whatever the level of nicotine in the cigarettes they smoke.

Which one of the following, if true, most helps to explain the finding of nicotine study?

A. Blood cannot absorb more nicotine per day than that found in the smoke from a package of the lowest-nicotine cigarettes available.
B. Smokers of the lowest-nicotine cigarettes available generally smoke more cigarettes per day than smokers of high-nicotine cigarettes.
C. Most nicotine is absorbed into the blood of a smoker even if it is delivered in smaller quantities.
D. The level of tar in cigarettes is higher in low-nicotine cigarettes than it is in some high-nicotine cigarettes.
E. When taking in nicotine by smoking cigarettes is discontinued, the level of nicotine in the blood decreases steadily
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First Attempt 710 - first-attempt-141273.html

The answer is A. If blood cannot absorb more nicotine than what is found in the lowest nicotine cigarettes, there is no reason higher nicotine cigarettes should produce higher levels of nicotine in blood samples.

B is tempting, but is not correct; the stem already tells us the study *only* looked at people smoking exactly one pack per day. So the study controlled for the number of cigarettes smoked. C tells us that low-nicotine cigarettes still deliver nicotine, which does nothing to explain why there is no difference between low and high nicotine smokes. Tar is irrelevant, so D is wrong. The wording of E is completely unclear, so it's hard to even evaluate. If it were the case that nicotine levels dropped very quickly moments after smoking, then E would be a very good answer here too, since that would mean no one has high nicotine levels at the end of the day besides people who just smoked a cigarette; the nicotine level of cigarettes would be irrelevant. I don't think that's what the question writer meant by E, however, even though it could be interpreted that way.

Because the writing of the question is quite bad, it is a bit tricky to answer; in C the word 'it' should clearly refer back to 'nicotine' for example, and the wording of E is so imprecise that it's impossible to know exactly what it means. Where is the question from?
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