When Stone B collides with Stone A during Test 2, Stone B stops and Stone A begins to move. Which statement BEST describes the momentum in Test 2?
A
Stone A moves away from Stone B at a velocity of 4 m/s, and the momentum is conserved.
B
Stone A moves away from Stone B at a velocity of 2 m/s, and the momentum is not conserved.
C
Stone A moves away from Stone B at a velocity of 4 m/s, and the momentum is not conserved.
D
Stone A moves away from Stone B at a velocity of 2 m/s, and the momentum is conserved.