Article 31 of Bahrain's Traffic Law Implementing Regulation places an extra following-distance duty on the driver of a slow vehicle or a vehicle longer than seven metres. What is that duty?

1. To drive at least 100 metres behind every other vehicle at all times
2. To leave a gap ahead large enough for another vehicle wishing to overtake to move into it
3. To keep as close as possible to the vehicle in front so the convoy stays compact
4. To stop every seven kilometres and let following traffic pass