题目选项分析

Smithtown University's fund-raisers succeeded in getting donations from 80 percent of the potential donors they contacted. This success rate, exceptionally high for university fund-raisers, does not indicate that they were doing a good job. On the contrary, since the people most likely to donate are those who have donated in the past, good fund-raisers constantly try less-likely prospects in an effort to expand the donor base. The high success rate shows insufficient canvassing effort.

Which of the following, if true, provides more support for the argument?

【选项】This year the average size of the donations to Smithtown University from new donors when the university's fund-raisers had contacted was larger than the average size of donations from donors who had given to the university before.