Please choose the correct answer to the question: A ball is thrown straight up. Which statement best describes the motion of the ball while the ball is at the maximum height?

Answer1: The speed and acceleration are constant. Answer2: The velocity is zero, and the acceleration is constant. Answer3: The speed and acceleration are changing. Answer4: The velocity is zero, and the acceleration is changing.

Answer format: answer1/answer2/answer3/answer4
Answer: answer2