The correct answer is A. Radical Republicans.
The Fifteenth Amendment gave people of color the right to vote, so D is definitely incorrect. B is incorrect too because labor union organizers wanted all workers to have the same rights. C is incorrect because by passing this Amendment, it would mean better prospects for women too. This leaves us with A, given that these Republicans were the ones who owned slaves in the first place.
Honestly I have no clue I’m still learning sorry
