Answer:
C. 800 N to the left.
Step-by-step explanation:
By the second law of newton, the net force applied on an object is equal to mass times acceleration. In this case, the caravan has a mass of 400 kg and an acceleration of 2 m/s² to the left. Then, the force the coupling exerts on the caravan is
F = (400kg)(2 m/s²)
F = 800 N to the left
Therefore, the answer is
C. 800 N to the left.