A laden rigid truck on a long Alpine-style descent has a working retarder and a six-speed gearbox. Which combination best follows Goal 1.2?

1. Highest gear, retarder off, service brakes applied lightly the whole way
2. Neutral, retarder at maximum, hazard lights from the top of the hill
3. ABS switched off so the retarder can lock the drive axle
4. A low enough gear that engine and retarder hold a stable speed, with brief service-brake applications only when speed still rises