A tyre’s adhesion to the road surface depends on what?

The selected combination is correct because a tyre's adhesion to the road surface is influenced by multiple factors.

1. Tyre Temperature: As tyres heat up from friction during driving, their grip on the road improves. This is important, especially in higher speed scenarios.

2. Road Conditions: The texture and material of the road surface play a significant role. Wet, icy, or poorly maintained roads can drastically reduce tyre adhesion.

3. Weather Conditions: External weather impacts such as rain, ice, or snow can change the road's condition, therefore affecting the tyres' grip.

In German traffic law, maintaining proper tyre conditions and understanding the effect of different variables on adhesion is crucial for safe driving. This knowledge helps drivers make informed decisions regarding speed and safety measures, particularly in adverse conditions.