[单选题]
A 2.0-kg mass moves with a speed of 5.0 m/s. It colp(h u*rydi6+4o weibr2au0o* lides head-on awn f(w8u-tn:with a 3.0 kg mass at rest. If the collision is ptwf- unwn:(a 8erfectly inelastic, 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
