Critical Reasoning

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 fundraisers,
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?

A. Smithtown University's fund-raisers were successful in their contacts with potential donors who
had never given before about as frequently as were fund-raisers for other universities in their
contacts with such people.
B. 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.
C. This year most of the donations that came to Smithtown University from people who had
previously donated to it were made without the university's fund-raisers having made any
contact with the donors.
D. The majority of the donations that fund-raisers succeeded in getting for Smithtown University
this year were from donors who had never given to the university before.
E. More than half of the money raised by Smithtown University's fund-raisers came from donors
who had never previously donated to the university.

I posted an explanation here:

https://www.beatthegmat.com/smithtown-t66628.html#299390

IMO Option C.

This directly supports the point that the university fund raisers were not doing a good job.

OA pls.