Explanation: the two vehicles behind the truck is moving at a constant speed because there is no change in velocity. The truck is changing directions AND speed (Acceleration/Velocity).
<em>It's C because when dealing with acceleration, you need velocity. The pickup truck has the velocity, meaning change in direction and speed. The two other cars are going at a constant rate of speed in a straight line. The pickup truck most likely has to slow down when changing its direction; therefore, answer C is your best option. <3</em>