题目选项分析

A certain city offers publicly owned, desirable billboard-advertising space at heavily discounted monthly rates to locally owned businesses. Since the implementation of this policy, the city has increased the amount of billboard space sold per month. Nevertheless, the city could increase its revenues by revoking these discounts.

Which of the following, if true, most strongly supports the claim above regarding the city's revenues?

【选项】The amount of discount generally offered is carefully calculated to represent the minimum needed to drive sales to local businesses.