(A) : A disc released from the top of a fixed inclined plane rolls down without slipping if the inclined plane is rough only
(R ) : Friction does no work in pure rolling

Options

A. Both (A) and (R ) are true and (R ) is the correct explanation of (A)
B. Both (A) and (R ) are true and (R ) is not the correct explanation of (A)
C. (A) is true but (R ) is false
D. Both (A) and (R ) are false

Answer

B