The picture below shows three elevators, each carrying a different number of people to different floors. If all the people weigh the same, which elevator is doing the most work? (Weight = Force, and Number of floors = Amount of displacement)

Select one:
a. Elevator 1 is doing the most work.
b. Elevator 2 is doing the most work.
c. Elevator 3 is doing the most work.
d. They're all doing the same amount of work.