Which of these circumstances is the proper way of transporting cargo on a trailer pulled by a passenger car?

In the photo, a red passenger car with a trailer covered with a red tarpaulin is parked by a street on a housing estate. The correct way to carry a load on a trailer is with the load secured against moving - answer A. An unsecured load (B) is prohibited, also at speeds of up to 30 km/h (C).

The Road Traffic Act states that a load placed on a vehicle should be secured against changing position or making excessive noise, and the devices used to fasten the load must be secured against loosening, hanging freely or falling off while driving; the load also must not affect the stability of the vehicle, make steering difficult or cover lights and plates. The rule has no exception for slow driving - at 30 km/h, sudden braking also moves an unfastened crate, which hits the side of the trailer or falls onto the road. A moving load changes the weight distribution of the trailer: weight behind the axle takes load off the tow hitch and makes the combination start to "snake", and this is one of the common causes of accidents with trailers. You fasten the load with straps to the anchor points, put heavier items low and above the axle, fasten the tarpaulin on all the hooks, and after the first few kilometres you stop and check the tension of the straps.

Legal basis: Art. 61 para. 2 point 2-4, para. 3 and 4 of the Road Traffic Act (Prawo o ruchu drogowym)