When assessing the elbow, a nurse asks a client to hold the arm out and turn the palm down. When the client performs this maneuver, the nurse is testing what?

A. Flexion refers to bending the joint, which does not apply when turning the palm down. B. Supination is the movement of turning the palm up, which is the opposite of what is being tested here. C. Rotation refers to the circular movement around a central point, but it does not specifically describe the action of turning the palm down. D. Pronation is the movement of turning the palm down, which is exactly what the client is doing when asked to perform this maneuver.