Hercules is walking forward while carrying a backpack on his back. Which of the following statements is true?
A. Work is not being done on the backpack because the backpacks direction of force is down, while Hercules direction of force is forward.
B.Work is being done on the backpack because both the backpacks's and Hercules direction of force are upward
C.Work is being done on the backpack because Hercules is carrying it on his back
D.Work is not being done on the backpack because the distance the backpack travels is not equivalent to the distance Hercules travels.