The answer is below.
Work Step by Step
a) The trunk is at rest and is not going to be moving, meaning that it has a constant velocity of 0. Since the velocity is constant, the net force is 0N. b) The trunk has a constant velocity, so the net force is 0N. c) The tension in the elevator is equal to the weight of the elevator and everything in it, so the elevator cable is exactly balancing gravity. Thus, the overall net force is 0N. d) The force of gravity is causing the trunk to accelerate downward, so the net force is downward.