17. One state adds a 7 percent sales tax to the price of most products purchased within its jurisdiction. This tax, therefore, if viewed as tax on income, has the reverse effect of the federal income tax: the lower the income, the higher the annual percentage rate at which the income is taxed.

The conclusion above would be properly drawn if which of the following were assumed as a premise?

(A) The amount of money citizens spend on products subject to the state tax tends to be equal across income levels.

(B) The federal income tax favors citizens with high incomes, whereas the state sales tax favors citizens with low incomes.

(C) Citizens with low annual incomes can afford to pay a relatively higher percentage of their incomes in state sales tax, since their federal income tax is relatively low.

(D) The lower a state’s sales tax, the more it will tend to redistribute income from the more affluent citizens to the rest of society.（A）

(E) Citizens who fail to earn federally taxable income are also exempt from the state sales tax.

今天把讨论贴都搜出来看了下还是不太明白A与题目的逻辑关系，麻烦哪位给讲一下？

试着帮你解一下，以前上新东方时费费讲过这个题.

首先这是个假设题，可以利用搭桥法

政府提高销售税

结论 the lower the income, the higher the annual percentage rate at which the income is taxed.

因为销售税是还在商品价格中的，所以购买同样价格的商品的销售税是相同的，所以在分别与两种收入相比，高收入分母大，低收入分母小，所以就可以的出结论了。