A Tractor $\mathrm{T}$ Is Pulling a Trailer $\mathrm{M}$ With a Constant Velocity $20 \mathrm{~m} / \mathrm{s}$

Multiple Choice

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

A) $600 \mathrm{~N}$ forward.
B) $450 \mathrm{~N}$ backward.
C) 0 .
D) $35 \mathrm{~N}$ forward.
E) $200 \mathrm{~N}$ backward.