A block of mass $$m$$, lying on a rough horizontal plane, is acted upon by a horizontal force $$P$$ and simultaneously by another force $$Q$$ acting at an angle $$\theta$$ from the vertical as shown. The block will remain in equilibrium if the coefficient of friction between the block and the surface $$S$$ is

A

at least $$\frac{P + Q\sin\theta}{mg + Q\cos\theta}$$

B

at least $$\frac{P + Q\cos\theta}{mg + Q\sin\theta}$$

C

equal to $$\frac{P + Q\sin\theta}{mg - Q\cos\theta}$$

D

equal to $$\frac{P + Q\cos\theta}{mg - Q\sin\theta}$$