Which amendment allows for the availability of procedures for voter registration at public agencies?

The correct answer is the 26th Amendment, which lowers the voting age to 18 and, in the context of voter registration, reflects a broader movement to increase voter participation among young people. This amendment emphasizes the importance of making the democratic process accessible to all citizens, including those who are newly eligible to vote. The procedures for voter registration at public agencies were also influenced by legislative measures, like the National Voter Registration Act of 1993, which aimed to simplify the registration process and make it more convenient for individuals to register to vote, particularly at places like public agencies.

The other amendments listed focus on different aspects of voting rights and do not pertain directly to the procedures surrounding voter registration. The 15th Amendment addresses voting rights irrespective of race, the 19th Amendment grants women the right to vote, and the 23rd Amendment provides electoral votes for the District of Columbia. Each of these amendments contributes significantly to expanding voting rights but does not specifically relate to the establishment of voter registration procedures at public agencies.