You are driving on the highway at 65 mph when it suddenly starts raining heavily. Visibility drops significantly. What is the BEST course of action?

1. Maintain speed but turn on wipers
2. Stop on the highway and turn on hazard lights
3. Switch to high beams for better visibility
4. Reduce speed, turn on low beam headlights, increase following distance, and pull off at the next exit if conditions worsen

Source: State DMV Official Driver's Manual