Fill in the blank.
Tyres have treads to ______ friction.
(A) increase
(B) decrease
(C) neglect
(D) overcome

Hint:The tyres of the vehicles are provided with the treads in between them. They have an important function to maintain the contact between the road and tyre. The rough surface has the maximum surface and the smooth and the soft surface have minimum friction.

Complete step by step answer:
The treads in tyres, do not have a direct influence in maintaining the friction between the roads and the tyres. The friction acts between the surface of the road and tyre, to maintain the safe travel of the vehicle. During normal days, there is no problem in maintaining the friction between these two surfaces.
But during the rainy days, the road is filled with water and muddy soil. This muddy water may stick into the tyres and reduce the friction between them. In order to avoid this situation, the treads are designed in the tyres to displace the amount of the water on the tyres. Hence the treads remove the watery and the muddy soil stuck in the tyres and increases the friction of it.

Thus the option (A) is correct.

Note:The tyres are made up of the thick low quality hard rubber. This is because the tyres while moving due to the friction force between the road and itself, a large wearing may produce. This wearing may cause failure of the use of the tyres.