Three blocks are placed on a smooth horizontal surface and along a straight line. Block-1 and Bl...

Three blocks are placed on a smooth horizontal surface and along a straight line. Block-1 and Block-3 have mass \( m \) each, and Block-2 has mass \( Mm \). Block-2 and Block-3 are initially stationary, while Block-1 is initially moving towards Block-2 with speed \( v \) as shown. Assuming all collisions are head-on and perfectly elastic, for what value of \( M / m \) will Block-1 and Block-3 have the same final speed?
(A) \( 5+\sqrt{2} \)
(B) \( 5-\sqrt{2} \)
(C) \( 2+\sqrt{5} \)
(D) \( 3+\sqrt{5} \)