题目选项分析

The city of Workney, in raising bus fares from $1.00 to $1.25, proposed that 18 fare tokens be sold for $20.00 to alleviate the extra burden of the fare increase on the city's poor people. Critics suggested alternatively that 9 fare tokens be sold for $10.00, because a $20.00 outlay would be prohibitive for poor riders

The alternative proposal depends on which of the following assumptions?

【选项】Fewer riders would regularly purchase 18 fare tokens at once than would purchase only 9 fare tokens at once