OA is A
C is out-of scope because of the below highlighted phrase
A clearly says that the donations came from previous donors who did few frequent donations in the past, which clearly shows that the fundraisers did not contact potential new donors.
(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.
Hope this helps.
KUDOS is a way to say Thank You