Assertion (A): When one body drives another by direct contact, their contact points must have equal component of velocity normal to the surfaces at the point of contact.
Reason (R): Two points in the same body must have the same component of velocity relative to third body, in the direction on the line joining the two points.
(a) Both A and R are true and R is the correct explanation of A
(b) Both A and R are true but R is not a correct explanation of A
(c) A is true but R is false
(d) A is false but R is true