Critical Reasoning

Addiction to the nicotine in cigarettes prevents many people from quitting smoking. To make quitting easier, lawmakers in Tarnia passed legislation that will reduce the average quantity of nicotine per cigarette by half over the next five years. Since the lower a smoker's nicotine intake is, the easier it is for the person to quit, the proportion of Tarnian's attempting to quit smoking who succeed in their attempts will probably increase significantly during the next five years.

Which of the following is an assumption on which the argument depends?

a) the strength of the person's nicotine addiction only depends on the amount of nicotine that the person regularly consumes.

b) most of the cigarette smokers in tarnia would quit smoking if they were not addicted to nicotine

c) it is unlikely that many tarnians who have not already become addicted to nicotine will become addicted to nicotine at some time over the next five years.

d) tania smokers addicted to nicotine will not generally compensate for the decreases in the amount of nicotine per cigarette by smoking more cigarettes.

e) all cigarettes currently sold in tarnia contain the maximum amount of nicotine permitted by law.



I narrowed my choices down to [spoiler]A & D[/spoiler] -- but chose A, which is wrong (OA = D).

My reasoning:[spoiler] Despite the use of "only" in answer choice A (which my CR guide tells me to be wary of in an assumption question type), I felt that D was outside the scope-- the argument is about addicted smokers who want to quit smoking, not about addicted smokers in general.[/spoiler]

Could someone please help me better understand why the correct answer is what it is.

Thanks!

Please use the spoiler function to hide the answer choices that you considered viable, along with the OA.

srk228 wrote:Addiction to the nicotine in cigarettes prevents many people from quitting smoking. To make quitting easier, lawmakers in Tarnia passed legislation that will reduce the average quantity of nicotine per cigarette by half over the next five years. Since the lower a smoker's nicotine intake is, the easier it is for the person to quit, the proportion of Tarnian's attempting to quit smoking who succeed in their attempts will probably increase significantly during the next five years.

Which of the following is an assumption on which the argument depends?

a) the strength of the person's nicotine addiction only depends on the amount of nicotine that the person regularly consumes.

b) most of the cigarette smokers in tarnia would quit smoking if they were not addicted to nicotine

c) it is unlikely that many tarnians who have not already become addicted to nicotine will become addicted to nicotine at some time over the next five years.

d) tania smokers addicted to nicotine will not generally compensate for the decreases in the amount of nicotine per cigarette by smoking more cigarettes.

e) all cigarettes currently sold in tarnia contain the maximum amount of nicotine permitted by law.

I narrowed my choices down to [spoiler]A & D[/spoiler] -- but chose A, which is wrong (OA = D).

Premise:
Lawmakers in Tarnia passed legislation that will reduce the average quantity of nicotine per cigarette by half, and the lower a smoker's nicotine intake is, the easier it is for the person to quit.
Conclusion:
The proportion of Tarnians attempting to quit smoking who succeed in their attempts will probably increase significantly.

Apply the NEGATION TEST.
When the correct answer choice is negated, the conclusion will be invalidated.

D, negated:
Tarnian smokers addicted to nicotine will compensate for the decreases in the amount of nicotine per cigarette by smoking more cigarettes.
Here, the passing of the law will induce smokers to smoke MORE CIGARETTES, invalidating the conclusion that the proportion of Tarnians attempting to quit smoking who succeed in their attempts will probably increase significantly.
Since this negation invalidates the conclusion, D is an ASSUMPTION: a statement that MUST BE TRUE for the conclusion in the argument to hold.

The correct answer is D.

A, negated:
The strength of a person's nicotine addiction does not depend only on the amount of nicotine that the person regularly consumes.
This negation seems to contradict the PREMISE that the lower a smoker's nicotine intake is, the easier it is for the person to quit.
A premise is a FACT.
It cannot be contradicted.
Eliminate A.