What type of warning device is required for emergency doors on school buses manufactured prior to July 1, 1970?

The correct answer indicates that an audible and visual electrical warning device is required for emergency doors on school buses manufactured prior to July 1, 1970. This regulation is in place to ensure the safety of passengers by providing clear warnings when the emergency exits are in use. The incorporation of both audible and visual signals ensures that the warning is not only seen but also heard, enhancing safety procedures. This dual-alert mechanism is crucial in preventing accidents or ensuring that proper attention is given to the opening of emergency doors, especially in situations where immediate evacuation is necessary.

While other answers suggest varying levels of warning devices, the requirement for both an audible and visual warning aligns with safety standards aimed at maximizing awareness and responsiveness in emergency situations.