[单选题]
A 2.0-kg mass moves with a speemb 43j8vhbi h+d l8jppq3q/1 g8fjd i,e of 5.0 m/s. It collides head-on with a 3.0 kg mass at rest. If the collision is perfectly pd, l iq1p/j3gq8j 8feinelastic, what is the speed of the masses after the collision?
A. 10 m/s
B. 2.5 m/s
C. 2.0 m/s
D. 0, since the collision is inelastic