While trying to lift a box, Emile, a nurse, bent down, keeping his legs straight and back horizontal to the floor, and lifted the object. Later that day, Emile's lower back started hurting. How could Emile have correctly lifted the box using proper body mechanics? A. By bending his knees and using his back muscles B. By keeping his neck bent and using his wrist muscles C. By bending his knees and keeping his back straight D. By keeping his legs straight and lowering his shoulders