A Tractor T Is Pulling a Trailer M with a Constant

Multiple Choice

A tractor T is pulling a trailer M with a constant velocity. If the velocity is 20 m/s and M = 200 kg and T = 500 kg, then the force on the trailer due to the tractor is (assume there is no friction or air resistance)

A) 600 N forward.
B) 450 N backward.
C) 200 N backward.
D) 35 N forward.
E) 0.