The 15th, 19th, and 26th amendments to the United States Constitution all relate to voting rights. These amendments expanded voting rights and eliminated various barriers to voting for different groups of people. Specifically, the 15th Amendment, ratified in 1870, granted African American men the right to vote and prohibited racial discrimination in voting. The 19th Amendment, ratified in 1920, gave women the right to vote, ensuring gender equality in voting. Lastly, the 26th Amendment, ratified in 1971, lowered the voting age from 21 to 18, granting 18-year-old citizens the right to vote. Therefore, the correct answer is (a) Voting rights.
