dwdwdw1986问：
CR9.21 In the year following an eight-cent increase in the federal tax on a packof cigarettes, sales of cigarettes fell ten percent. In contrast, in the yearprior to the tax increase, sales had fallen one percent. The volume ofcigarette sales is therefore strongly related to the after-tax price of a pack ofcigarettes.
The argument above requires which of following assumptions?
A. During the year following the tax increase, the pretax price of apack of cigarettes did not increase by as much as it had during the yearprior to the tax increase.
B. The one percent fall in cigarette sales in the year prior to tax increasewas due to a smaller tax increase.
C. The pretax price of a pack of cigarettes gradually decreased throughoutthe year before and the year after the tax increase.
D. For the year following the tax increase, the pretax price of a pack ofcigarettes was not eight or more cents lower than it had been theprevious year.
E. As the after-tax price of a pack of cigarettes rises, the pretax price alsorises.
