Block A (mass =5 kg ) with an initial velocity of 10 m/s right, collides with block B (mass =10 kg ) which is at rest. The final velocity of B is 6 m/s right. What is the final velocity (magnitude and direction) of A? The surface is frictionless. A. 4 m/s right B. 0 C. 2 m/s left D. 4 m/s left E. 2 m/s right