What does the Libro del Nuevo Conductor Profesional expect a driver to know about the fire extinguisher carried on a commercial vehicle?

1. That it is optional on buses
2. That the vehicle carries one, where it is mounted, and the protocol for using it — including approaching with the wind at your back, aiming at the base of the flames and sweeping, and evacuating if the fire is not quickly controlled
3. That water is the correct agent for a fuel or electrical fire
4. That only sand buckets are required