A driver approaching your commercial vehicle from behind is flashing their headlights and moving erratically. What hazard does this indicate, and how should you respond?

1. The driver wants to race; ignore them and maintain speed
2. The driver may be impaired or aggressive; safely move to the right lane, increase space, and let them pass
3. The driver is signaling that your lights are too bright; dim your headlights
4. The driver is a law enforcement officer; pull over immediately