Correct Answer: C
Explanation:
The embittered benefactor thinks of them as ingrates (ungrateful persons) because they do not thank him sufficiently for his generosity.
He does not think of them as misers (hoarders of wealth): although they are stingy in expressing tanks, they are extravagant in spending money. He certainly does not think of them as louts (clumsy oafs), prigs (self-righteous fussbudgets), or renegades (traitors): the specific attribute he resents in them is ingratitude, not cloddishness, self-satisfaction or perfidy.