Which vehicles must keep a gap ahead that lets overtaking traffic pull back in, when driving outside a built-up area in Belarus?

1. Vehicles longer than 10 metres, and vehicles limited to or incapable of exceeding 40 km/h
2. Every vehicle with a permissible maximum mass over 3.5 tonnes
3. Only articulated road trains carrying dangerous goods
4. No such requirement exists in the Belarusian Rules