Final answer:
You should put on your hazard lights as a warning option (B) before reversing your bus. This helps alert others to your intentions and contributes to the safety of everyone involved.
Step-by-step explanation:
Before reversing your bus, you should put on your hazard lights as a warning option (B). This action serves to alert other road users and pedestrians of your intention to reverse, increasing safety for everyone around the vehicle. It is essential to ensure that the area around the bus is clear of obstacles, people, and other vehicles before reversing. While revving your engine or sounding your horn can be used as a warning in some situations, these actions can also cause confusion or be disruptive. Disembarking to check all around the vehicle can be a good practice, especially in situations where visibility is poor or when maneuvering in tight spaces.