What should you ensure about the trailer's landing gear before driving?

Answer: B — That it is fully raised and locked

Before driving, it is crucial to ensure that the trailer's landing gear is fully raised and locked. This is essential for safety and to prevent any potential damage to the trailer or disconnecting from the truck while in transit. If the landing gear is not properly raised and locked, it could drag on the ground, leading to a risk of an accident, trailer damage, or even a jackknife situation. Furthermore, having the landing gear fully raised and locked ensures that there are no obstructions when making turns and maneuvering. It is also a common requirement in most trucking regulations to ensure that the gear is in the correct position before starting the journey. The landing gear serves as a support structure when the trailer is not coupled to the truck; however, once the truck and trailer are connected and ready for travel, having the gear properly stowed is critical for safe operation.