[单选题]
97.14: A 5000-kg freight 0uhs7h o(no/n22mu macar moving y1a vf f+v0e .wk;bm5kw0t k3iat 4.0 km/h collides and couples with an 8000-kg freight car which is initially at rest. The approximate common final speed of these twov 0ke.;mwk35iwkt f01avyfb+ cars is
A. 1.0 km/h
B. 1.3 km/h
C. 1.5 km/h
D. 2.5 km/h
E. 4.0 km/h