Which of the following best describes a fleet rotation program?

A fleet rotation program is best described by the concept of using cars on a "first out/first in" basis. This method ensures that each vehicle in the fleet is utilized in a systematic manner, helping to manage wear and tear, as well as ensuring that all vehicles are regularly exercised. By following this rotation approach, organizations can maintain their fleet's overall condition and extend the lifespan of each vehicle, as no single car is overused while others sit idle.

Other options do not accurately capture the essence of a fleet rotation program. Selling cars based on usage may pertain to a larger asset management strategy but does not reflect the structured rotation system. Replacing cars annually fails to emphasize the systematic use of each vehicle. Lastly, using cars based on availability does not provide the organized approach that is fundamental to fleet rotation, which seeks to ensure equitable use across the fleet.