Answer:
B. the 15th amendment.
Explanation:
The 15th amendment states, "The right of citizens of the United States to vote shall not be denied or abridged by the United States or by any State on account of race, color, or previous condition of servitude."
Meanwhile, literacy tests were insanely difficult tests designed only to be taken by African Americans. Ku Klux Klan violence was violence against people of color. Poll taxes were taxes you had to pay in order to vote, meaning poor people (meaning mostly POCs because racism galore) couldn't vote.