A vehicle makes a forced stop at night on an unlit road where stopping is prohibited, and its hazard warning signal is faulty. What does the Law 'On Road Traffic' allow the driver to use?

1. Nothing — the driver must simply leave the vehicle and walk to the nearest settlement for help.
2. The vehicle's high-beam headlights, left switched on and aimed down the road.
3. A portable lamp with a flashing red light, set out according to the same rules as the emergency stop sign.
4. The horn, sounded at regular intervals until assistance arrives.