At what maximum speed are you allowed to drive on the road beyond these signs if you are hauling another passenger car?

Why?

The lower sign in the photo, D-43, marks the end of the built-up area and determines which towing limit applies. Outside a built-up area, a car towing another car may travel at no more than 60 km/h, so B is correct. The 30 km/h towing limit applies within built-up areas, while 90 km/h is not permitted when towing another car.

Art. 31 ust. 1 pkt 1 Prawa o ruchu drogowym