If a person pushes a wall but fails to displace it, then he does no work (A). In physics, work is defined as the product of force and displacement in the direction of the force. When there is no displacement, regardless of the magnitude of the force applied, the work done is zero. Even though the person exerts force against the wall, if the wall does not move, there is no change in the wall’s position, and hence no work is accomplished. Option (B) is incorrect because negative work implies that energy is being taken away from the system, which doesn’t apply here. Option (C) implies some positive work, but there’s no work done if there’s no displacement. Option (D) is incorrect because maximum work would imply achieving the greatest possible displacement, which isn’t the case if the wall remains stationary. Therefore, the correct option is (A) No work.