Answer:
[tex]\boxed {\boxed {\sf D. \ 15th \ Amendment}}[/tex]
Explanation:
Let's analyze each answer choice.
A. Literacy tests
These were used to suppress African American suffrage. Most African Americans didn't have equal educational opportunities, so they couldn't pass these extremely confusing tests.
B. Intimidation of the Ku Klux Klan
This was also used. This group used hate, intimidation, and violence to stop African Americans from voting.
C. Poll taxes
These required citizens to pay a fee before voting. Since African Americans didn't have the same opportunities for jobs and education, they couldn't afford the tax, so they couldn't vote.
D. 15th Amendment
This was not used. This amendment gave African Americans the right to vote. Therefore, this is the best choice because it wasn't used to keep them from voting.
