How should a driver adjust following distance when driving behind another vehicle at night on an unlit rural road?

1. Increase following distance to at least 3 to 4 seconds to compensate for reduced visibility and limited headlamp range
2. Decrease following distance to stay close to the preceding vehicle's rear lights
3. Maintain a 1-second gap while keeping high beams turned on continuously
4. Follow directly on the bumper to avoid missing road curves