Which observation BEST demonstrates Newton's first Law of Motion? A. A small rock thrown at a trashcan cannot knock it over, but a more massive rock thrown with the same
force at the same trashcan can knock it over.

B. A football thrown by an NFL quarterback has greater acceleration than a football you throw.

C. A book placed beside you in the back seat of a car slides to the floor as the car stops suddenly.

D. An astronaut weighs more on Earth than he does on the moon, but is mass does not change.