What is the mandatory safety procedure when reversing a large passenger bus in a terminal yard or cramped roadway?

1. Assign a conductor or ground spotter to guide from a visible rear position, turn on hazard flashers, check all mirrors and reversing cameras, and reverse at low walking speed
2. Reverse rapidly without looking because the bus has an audible reversing beeper
3. Rely solely on looking out the driver's side window while ignoring the right side mirror
4. Instruct passengers to reverse the bus while the driver rests