What results in specific risks to motorcyclists?

The selected combination is correct because each option highlights a specific risk that can significantly affect motorcyclists.

1. Riding with the visor open can lead to reduced visibility and increased exposure to debris or insects, which can distract the rider or impair vision.
2. Riding in heavy rain can decrease traction and visibility, making it much harder to control the motorcycle and increasing the likelihood of accidents.
3. Changes in the road surfacing, such as potholes or uneven surfaces, can create unpredictable handling conditions and potentially cause loss of control.

In Germany, the road safety rules emphasize the importance of understanding environmental conditions and equipment to mitigate risks for motorcyclists. Recognizing and addressing these specific risks helps ensure safer riding practices.