Answer:
D. a roller coaster at the top of a hill
Explanation:
Potential energy is the energy held by the object because of its position relative to other objects around it. Potential energy is the energy it is going to have (future) kinetic energy is energy that it is currently having. On a roller coaster, when the cart is on the top of the hill, it has the potential energy, when it is falling down the hill, it produces kinetic energy! Hope this helped!