Which of the following actions is MOST critical if you are caught in a sudden, severe sandstorm on a highway, causing visibility to drop to near zero?

1. Stop immediately in your current lane and wait for the storm to pass.
2. Pull over to the hard shoulder as far as possible, turn on hazard lights, and turn OFF headlights.
3. Turn on your high beams and follow the taillights of the vehicle in front of you.
4. Slow down significantly but keep moving to avoid being a stationary target.