In the year 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.

Which of the following, if true, would most strengthen the argument above?

【选项】During the year after the tax increase, there was a greater variety of cigarettes on the market than there had been during the previous year.