Under the Austrian rules on towing trailers (KFG 1967 § 104), how many agricultural trailers may an agricultural tractor (Zugmaschine) tow at the same time?

1. Up to two agricultural trailers, provided all technical, braking and marking conditions are satisfied
2. Only one trailer, unless the Landeshauptmann grants an individual permit
3. Up to three trailers, provided the combination stays within 18.75 m
4. Any number of trailers, as long as each one carries a 25 km plate