What is the proper action for a bus driver who encounters a severe thunderstorm with high crosswinds and fallen tree branches on a highway?

1. Accelerate to 100 km/h to pass the storm quickly
2. Reduce speed significantly, increase following distance, scan for road debris and standing water, and avoid stopping under large trees or unstable billboards
3. Stop in the left active lane with lights off
4. Instruct passengers to get out and stand in the open rain