Which warning plate is correctly mounted?

Your answer is correct.

The warning plates on vehicles like this tractor must be mounted at the outermost edges to clearly indicate the vehicle's width. This ensures that other drivers can easily see the widest point and adjust their distance accordingly. In the right example, the plates are positioned correctly on the outer sides of the vehicle.

If the warning plates are mounted closer to the center or improperly, it can be misleading and dangerous because other road users may underestimate the vehicle's width. Therefore, following this rule is important for safety on the road.