A block of mass M is released from point P on a rough inclined plane with inclination angle $\Theta$, shown in the figure below. The coefficient of friction is $\mu$. If $\mu$< tan$\Theta$, then the time taken by the block to reach another point Q on the inclined plane, where PQ = s, is
(a) $\sqrt{\frac{2s}{g \cos \Theta \left ( \tan \Theta -\mu \right )}}$ 
(b) $\sqrt{\frac{2s}{g \cos \Theta \left ( \tan \Theta +\mu \right )}}$ 
(c)$\sqrt{\frac{2s}{g \sin \Theta \left ( \tan \Theta -\mu \right )}}$ 
(d) $\sqrt{\frac{2s}{g \sin \Theta \left ( \tan \Theta +\mu \right )}}$ 