[单选题]
A 3.0-kg object moves r.8*w5+ myckwt9wyr vqk*x*bh/skxg: vv4+p to the right at 4.0 m/s. It collides in a perfectly inelastic collisqvh+* svk:g x/4 pb*kxion with a 6.1 kg object moving to the left at 2.0 m/s. What is the total kinetic energy after the collision?
A. $72 \; J$
B. $36 \; J$
C. $24 \; J$
D. $0 \; J$
