The coupling pins of your trailer hitch have a diameter of 38 mm when new. What should you note regarding wear?

In German traffic regulations, the wear limits on trailer coupling pins ensure safety when towing. The coupling pin's diameter must not fall below 36.5 mm uniformly across the entire coupling surface to maintain a secure connection; a smaller diameter increases the risk of failure. Additionally, the lower pin guide should not have excessive free play, as this could cause instability or detachment while driving. Allowed wear must be symmetrical and within these strict limits to guarantee reliable coupling. Therefore, both conditions—minimum diameter and limited play—are essential, and partial wear or uneven reduction is not acceptable. This is why options 1 and 2 are correct and must be observed together.