Assertion: A block of mass $m$ is at rest on a inclined surface of inclination $\theta$. Normal contact force between block and surface is $m g \cos \theta$.
Reason: If block of mass $m$ is at rest on inclined surface of inclination $\theta$. Friction force on the block is $m g \sin \theta$
(A) $\mathrm{A}$
(B) $\mathrm{B}$
(C) $\mathrm{C}$
(D) D