What must you remember after you have coupled up a trailer to an automatic trailer coupling?

The selected combination is correct because both aspects are essential for safely coupling a trailer.

1. The coupling pin must be fully engaged ensures that the trailer is securely attached to the vehicle, preventing any accidental disconnection while driving.

2. The position of the control pin indicates whether the coupling mechanism is locked properly. This is crucial for safety, as a correctly positioned control pin prevents the trailer from detaching unexpectedly.

Both of these checks are necessary according to German traffic regulations to ensure that the trailer will remain secure during transit, thus enhancing safety on the road. Not addressing these points can lead to serious accidents or violations of traffic laws.