Read the following list, which shows some examples of Jim Crow laws, and answer the question below.

• Florida prohibited marriage between certain groups of people.
• Alabama required railroad stations to have separate waiting rooms for African Americans.
• Oklahoma required that African Americans pass a literacy test before being allowed to vote.
• Mississippi required racially segregated public schools.

–Source: U.S. National Parks Service

Based on this list, which state was in direct violation of the Fifteenth Amendment?

A. Alabama

B. Florida

C. Mississippi

D. Oklahoma