What documentation must a school bus driver carry at all times?

Answer: B — Commercial driver’s license and medical certificate

A school bus driver is required to carry a commercial driver’s license and a medical certificate at all times because these documents are crucial for ensuring the driver meets the necessary qualifications to operate a school bus. The commercial driver’s license (CDL) reflects that the driver has passed the specific tests required for driving larger vehicles and understands how to operate them safely. The medical certificate confirms that the driver is physically fit to drive a school bus, adhering to health standards established for commercial drivers. While registration documents, insurance papers, and emergency contact information are important for various reasons, they do not specifically verify the driver's ability to safely and legally operate a school bus, which is why they are not the primary documentation required by law for school bus drivers.