谁能给我耐心解释

When people  evade income taxes by not declaring taxable income,a vicious cycle results.Tax evasion forces lawmakers to raise income tax rates,which causes the tax burden on nonevading taxpayers to become heavier.This,in turn, encourages even more taxpayers to evade income taxes by hiding taxable income.

The vicious cycle decrisibed above could not result unless which of the following were true?

CWhen law makers establish income tax rates in order to generate a certain level of revenue,they do not allow adequtely for revenue that will be lost through evasion.

我无法理解，这个defender，谁能教教我啊？详细点！

楼上的分析让我明白清楚些了,正好想到OG上另一个题目就增加警察人数的,警察人数增加到一定程度起威慑作用犯罪率就低了,从而不用多余的司法机关也不要付增加他们的费用了.(都是达到 ....level).