Which of the following best describes an action-reaction pair? a. the moon pulls on earth, and earth pulls back on the moon. b. a bed sits on the floor, and earth's gravity pulls down on the bed. c. a television pushes down on a shelf, and the shelf pulls the television down. d. you kick a wall, and the wall pulls on your foot.

An action-reaction pair would be a pair in which one of the elements exerts a force on the other element (action), and then the other element would respond to this force by exerting another force in the opposite direction (reaction).

From the given choices, we will see that:
For choice A, the moon exerts a force on the earth by pulling it (action) and the earth responds to this force by pulling the moon (reaction in opposite direction of the action).

Therefore, the correct choice would be: 
A. The Moon Pulls on Earth, and Earth pulls back on the moon.