The main function of the tread pattern on tyre is that

A. The tread grooves pass air between the tyre and road surface, thereby preventing tyre from overheating

B. The crests between the tread grooves absorb road noise

C. In wet conditions, the tread grooves expel water that is drawn between the tyre and road surface

D. The tread pattern protects the tyre's inner carcass from small stones and pieces of glass