Two bodies A and B of same mass undergo completely inelastic one dimensional collision. The body A

Two bodies A and B of same mass undergo completely inelastic one dimensional collision. The body A moves with velocity v 1 while body B is at rest before collision. The velocity of the system after collision is v 2 . The ratio v 1 : v 2 is (1) 1 : 2 (2) 2 : 1 (3) 4 : 1 (4) 1 : 4