What should be the minimum coefficient of static friction between the plane and the cylinder, for the cylinder not to slip on an inclined plane?
(a) $\frac{1}{3} \tan \theta$
(b) $\frac{1}{3} \sin \theta$
(c) $\frac{2}{3} \tan \theta$
(d) $\frac{2}{3} \sin \theta$