What must you check before coupling up a multiple-axle trailer?

You answered correctly. Before coupling a multiple-axle trailer, it is essential to check that the trailer is secured against rolling away, which means using the parking brake or wheel chocks. This prevents accidents and ensures safety during the coupling process. You must also ensure that the towing fork is correctly adjusted so the trailer attaches securely to the towing vehicle. Checking the trailer’s air brake tanks are full is not required before coupling; this is an operational check that would follow later. Always make sure the trailer is secure and properly prepared before connecting to avoid dangerous situations.