A sphere of mass m moving with constant velocity $V$ collide head on with another stationary sphere of same mass. If e is the coefficient of restitution then the ratio of the final velocities of the first and second sphere is

Question

$$\begin {array} {1 1} (a)\;\frac{1+e}{1-e} & \quad (b)\;\frac{1-e}{1+e} \\ (c)\;\frac{e}{1-e} & \quad  (d)\;\frac{1+e}{e} \end {array}$$