Which of the following is a requirement for operating a school bus in Arizona?

Operating a school bus in Arizona requires a special license endorsement. This endorsement ensures that the driver has met specific criteria and has undergone the necessary training to safely transport students. The endorsement is critical because it confirms that the driver is knowledgeable about the unique challenges associated with driving a school bus, such as traffic laws relevant to school zones, the proper procedures for loading and unloading children, and the requirements for maintaining a safe environment in and around the bus.

The other options do not meet the full scope of requirements for operating a school bus in Arizona. Driving experience, health examinations, and written tests may contribute to a driver's overall qualifications, but without the specific endorsement, drivers would not be legally permitted to operate a school bus. Therefore, the necessity of a special license endorsement stands out as the foundational requirement in this context.