In the event of a vehicle breakdown or accident on an ordinary road outside built-up areas, where MUST the warning triangle (triangle de présignalisation) be placed?

1. At least 30 meters behind the disabled vehicle on straight sections, and further back before blind crests or sharp bends
2. Directly against the rear bumper of the disabled vehicle
3. On the vehicle's roof next to the luggage rack
4. Exactly 2 meters behind the front driver's door