4. (3 points) A block is pushed such that it starts sliding up a rough incline. It gradually slows down, turnsaround, and slides back down to its starting point. Which

of the following statements is true about the workdone by gravity over the round trip? Explain your anşwer. A) Gravity did a net positive work B) Gravity did a net negative work C) Gravity did no net work D) There is no way to tell how much work gravity did.