Before loading or unloading the truck, what action should drivers always take?

The correct action that drivers should always take before loading or unloading the truck is to set the brakes. This is crucial for safety, as ensuring that the vehicle is securely positioned prevents it from rolling or shifting unexpectedly during the loading or unloading process. Setting the brakes stabilizes the vehicle, allowing the driver and any personnel involved in the loading and unloading to work safely without the risk of movement.

Starting the engine may seem necessary for certain operations, but it can introduce danger if the vehicle is not secure. Lowering the landing gear is important for trailers but is not a universal action required for all trucks before loading or unloading. Removing the load cannot be performed unless the area is secure, so it logically follows that the brakes must first be secured before any other actions.