Please choose the correct answer to the question: As a heavy metal ball rolls down a hill, it goes faster and faster. Which statement is true?

Answer1: The ball's potential energy is changing to kinetic energy. Answer2: The ball is gaining potential energy from the hill. Answer3: The ball is rapidly losing kinetic energy as it rolls down the hill. Answer4: The ball will continue gaining kinetic energy until it stops.

Answer format: answer1/answer2/answer3/answer4