A plate of mass $$M$$ is placed on a horizontal frictionless surface $$S$$. A block of mass $$m$$ is placed on the plate. The coefficient of dynamic friction between the block and the plate is $$\mu$$. If a horizontal force $$F = 2\mu mg$$ is applied to the block as shown, the acceleration of the plate will be

A

$$\frac{\mu mg}{M}$$

B

$$\frac{\mu mg}{m + M}$$

C

$$\frac{2\mu mg}{M}$$

D

$$\frac{2\mu mg}{m + M}$$