求大家指点一下这道题！

suri122

In the past, every ten-percentage-point increase in cigarette prices in the country of Coponia has decreased per capita sales of cigarettes by four percent.  Coponia is about to raise taxes on cigarettes by 9 cents per pack.  The average price of cigarettes in Coponia is and has been for more than a year 90 cents per pack.  So the tax hike stands an excellent chance of reducing per capita sales of cigarettes by four percent.
Which of the following is an assumption on which the argument depends?

A.    Tobacco companies are unlikely to reduce their profit per pack of cigarettes to avoid an increase in the cost per pack to consumers in Coponia.
B.    revious increases in cigarette prices in Coponia have generally been due to increases in taxes on cigarettes.
C.    Any decrease in per capita sales of cigarettes in Coponia will result mainly from an increase in the number of people who quit smoking entirely.
D.    At present, the price of a pack of cigarettes in Coponia includes taxes that amount to less than ten percent of the total selling price.
E.    The number of people in Coponia who smoke cigarettes has remained relatively constant for the past several years.

选A 为什么呢？

ayy90

烟价格上涨10%。销量下4%。正负征收10%税收，那销量就会下4%

缺乏税收和价格的关联。因此
假设：生产商会把征得税收放到价格里，让消费者承担，这样价格也就涨了10%