GWD3-Q31请教！

GWD3-Q31:

Although most smoking-related illnesses are caused by inhaling the tar in tobacco smoke, it is addiction to nicotine that prevents most smokers from quitting.  In

an effort to decrease the incidence of smoking-related illnesses, lawmakers in Sandonia plan to reduce the average quantity of nicotine per cigarette by half over the next five years.  Unfortunately, smokers who are already addicted to nicotine tend to react to such reductions by smoking correspondingly more cigarettes.

The information above most strongly supports which of the following predictions about the effects of implementing the Sandonian government’s plan?

1. The average quantity of tar inhaled by Sandonian smokers who are currently addicted to nicotine will probably not decrease during the next five years.
2. Sandonian smokers who are not already addicted to nicotine will probably also begin to smoke more cigarettes during the next five years than they had previously.
3. The annual number of Sandonian smokers developing smoking-related illnesses will probably decrease during the next five years.
4. The proportion of Sandonians attempting to quit smoking who succeed in that attempt will probably decrease during the next five years.
5. The number of Sandonians who quit smoking during the next five years will probably exceed the number who quit during the last five years.

通过排除法，好像答案只能选A，可是仔细看了一下，觉得原文与提目有偷换概念的意思。原文中说减少的是nicotine, 而提干A中说的是tar没有减少。我原来选A，是根据原文说虽然每只香烟中nicotine的数量减少了一半，但是每个人吸的数量多了，所以应该是nicotine的数量没有减少，但A选项说的是tar的数量没有减少。我觉得应该翻倍才对。（通过查询nicotine和tar好像完全是不同的事物）。如果这样理解的话，是不是A选项也对呢？

极度迷惑中。。。。。。。。。。。。。。