What should you ensure is operational before leaving the bus stop?

Ensuring all doors are closed securely before leaving the bus stop is critical for the safety of the passengers. It prevents individuals from accidentally falling out of the bus and ensures that all passengers, especially children, are safely on board before the bus departs. A securely closed door also protects the bus from unauthorized entry while it is in motion.

In contrast, while activating warning lights is important for safety and alerts other road users of a school bus in operation, this action typically occurs when the bus is preparing to stop rather than when leaving. Achieving top speed is not relevant at bus stops, where safety and passenger safety are the primary concerns. Seatbelt fastening is essential but primarily applies to the passengers rather than a procedure that must be checked before departure; it is the responsibility of passengers to buckle up once seated.