Under ADR 8.3.5, what strict operational prohibition applies to members of the vehicle crew regarding smoking and open flames near dangerous goods transport units?

1. Smoking is permitted during unloading of Class 3 liquids if standing 2 meters away
2. Smoking (including e-cigarettes) is prohibited during handling operations and in the vicinity of vehicles
3. Smoking is permitted only when carrying Class 8 corrosive substances
4. Smoking is permitted inside the cab with windows closed