What is the safest action to take if you are blinded by the high-beam headlights of an oncoming vehicle at night?

1. Turn on your own high beams to blind the other driver in retaliation
2. Look toward the left-hand verge/edge of your road lane, slow down, and use the road markings as a guide
3. Close both eyes until the oncoming vehicle passes
4. Switch off your headlights completely to improve night vision