Explanation
Correct answer: C.
Choice C is the best answer. We’re told that charities that pay donors back for nuisance costs will attract a few large donors instead of many small donors. This suggests that nuisance costs are not linked to donation size.
Why the other choices are wrong
Choice A
Choice A is incorrect. This doesn’t fit the logic of the text. If nuisance costs are supplemental to (meaning in addition to) donation size, that wouldn’t result in charities that compensate donors for those costs attracting a few large donors over many small donors.
Choice B
Choice B is incorrect. This doesn’t fit the logic of the text. If nuisance costs can predict donation size, that wouldn’t necessarily result in charities that compensate donors for those costs attracting a few large donors over many small donors.
Choice D
Choice D is incorrect. This doesn’t fit the logic of the text. If nuisance costs are subsumed in (meaning included in) donation size, that wouldn’t result in charities that compensate donors for those costs attracting a few large donors over many small donors.