What combination of practices ensures safety when parking a trailer?

Using chocks and placing the transmission in neutral is the safest combination of practices when parking a trailer. This method ensures stability and prevents the trailer from rolling.

Chocks are wedges or blocks placed against the wheels of the trailer, providing an additional layer of security by physically preventing movement. They are particularly important on inclines or uneven ground. When the transmission is in neutral, it removes the engine’s power from the wheels, allowing the chocks to do their job effectively without any risk of the trailer moving unexpectedly.

In contrast, options involving leaving the transmission in drive could lead to unanticipated movement if the vehicle rolls in any direction. Similarly, turning the wheels outward can help guide a trailer but does not offer as reliable a solution as using chocks, which are specifically designed to prevent unexpected motion. Overall, using both chocks and placing the transmission in neutral maximizes safety and minimizes the risk of accidents when parking a trailer.