[单选题]
A 3.0-kg object moves to the right atmsdzc sv)b(b(k. e)g-p2zrx9 4.0 m/s. It collides in a perfectly il mhu(+-8g y/ svxab2dnelastic co-+vbdg/(h sam8 u2lyxllision 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. $0 \; J$
