【请教】GWD-T-9-Q4

T-9-Q4             D

In the years following an eight-cent increase in the federal tax on a pack of cigarettes, sales of cigarettes fell ten percent. In contrast, in the year prior to the tax increase, sales had fallen one percent. The volume of cigarette sales is therefore strongly related to the after-tax price of a pack of cigarettes.
            

The argument above requires which of the following assumptions?

A.    During the year following the tax increase, the pretax price of a pack of cigarettes did not increase by as much as it had during the year prior to the tax increase.

B.    The one percent fall in cigarette sales in the year prior to tax increases was due to a smaller tax increase.

C.    The pretax price of a pack of cigarettes gradually decreased throughout the year before and the year after the tax increase.

D.    For the year following the tax increase, the pretax price of a pack of cigarettes was not eight or more cents lower than it had been the previous year.

E.     As the after-tax price of a pack of cigarettes rises, the pretax price also rises.

D项确实是典型的not + weaken: 去掉not，则the yeat following the tax increase的pretax price比the previous year低eight or more cents。假设恰好低eight cents，那么增税后，after-tax price就跟previous year的价格一样。两年价格一样，则导致sales不一样的原因就不一定是after-tax price，对原文weaken.

但若低more than eight cents呢，反向变化，也能说明sales related to after-tax price???原文只说related,并没说正相关还是负相关啊？？？

请各位大虾指教！！！

谢谢！！！