This question has Statement I and Statement II. Of the four choices given after the Statements, choose the one that best describes the two statements. 
Statement-I: A point particle of mass m moving with speed v collides with stationary point particle of mass M. If the maximum energy loss possible is given as $f\left(\frac{1}{2}m{v}^2\right)$ then $f=\frac{m}{M+m}.$
Statement-II: Maximum energy loss occurs when the particles get stick together as a result of the collision.