The movement of the leg laterally then medially, with knee straight is referred to as:

A. Flexion involves decreasing the angle between two body parts, such as bending the knee or elbow, not moving the leg laterally. B. Abduction is the movement of a body part away from the midline of the body. In this case, moving the leg laterally fits this description. C. Adduction refers to movement toward the body's midline, the opposite of abduction. D. Extension involves straightening a body part, such as straightening the knee, which does not match the description of moving the leg laterally and medially.