When driving a tractor with a loaded trailer, what should you do before entering a long section of the road going upwards?

In the photo, a steep dirt track climbs uphill between fields. Before driving up a long hill with a loaded trailer, you engage a gear that lets you get up it without changing down - answer A.

Changing gear uphill with a heavy trailer is a moment when the drive is disconnected - the combination immediately loses speed, and on a steep climb it may stop or start rolling back before you engage a lower gear. That is why you choose the gear before the hill, judging its length, its steepness and the mass of the load. Speeding up in the highest gear (answer B) usually ends with the engine labouring halfway up the climb and a nervous change down at the worst moment. Changing down to field gears "in any case" (answer C) is an exaggeration - on a gentle hill a road gear is enough, and driving in a field gear when it is not needed only slows traffic down. If the combination still stops, you brake and move off again in a low gear, making sure that you do not roll backwards.

Legal basis: Art. 19 para. 1 of the Road Traffic Act (Prawo o ruchu drogowym)