Which of the following is a valid medical requirement for a sport pilot?

For a sport pilot, the valid medical requirement is to have a valid U.S. driver's license. This is an alternative to the traditional medical certification process and recognizes that many individuals already undergo regular medical checks to maintain their driver's license.

Under the regulations governing sport pilot privileges, a driver's license serves as an adequate means of demonstrating medical fitness, provided that the pilot is not aware of any medical condition that would make them unfit to fly. This flexibility aims to encourage participation in aviation by reducing regulatory barriers for those who seek to fly light-sport aircraft.

In contrast, holding a medical certificate, whether second-class or another class, is not a requirement for sport pilots, making options involving different levels of medical certificates or providing extensive medical documentation irrelevant in this context.