Which of the following must be documented in a sport pilot's logbook?

The correct choice indicates that a sport pilot must document their biennial flight review and recent landings in their logbook. This requirement is rooted in both regulatory oversight and safety considerations.

The biennial flight review serves as a proof of proficiency, indicating that the pilot has undergone a formal evaluation of their flying skills and knowledge every two years. This ensures that sport pilots maintain a certain level of competency and stay updated on any changes in regulations or flying techniques. Documenting recent landings is crucial as it reflects the pilot's experience and current flying status, with emphasis on the importance of practice and familiarity with aircraft operations.

While other options may seem relevant, they do not hold the same regulatory requirement as the biennial flight review and recent landings. Flight maneuvers practiced do not need to be logged for regulatory purposes, nor is there a requirement to document an annual checkride or employment history in aviation for sport pilots. The focus is on ensuring that pilots are adequately trained and proficient to operate their aircraft safely.