A driver checks the bus interior and finds the restroom emergency buzzer is not working. Why does this matter for the Passenger endorsement material?

1. Maryland lists signaling devices, including the restroom emergency buzzer if present, as required safe-working interior items
2. The restroom buzzer is only a comfort feature and never part of inspection
3. The buzzer is checked only after a crash
4. The buzzer matters only if the bus is carrying hazardous materials