What are the primary bones of the human arm?

The primary bones of the human arm are the humerus, radius, and ulna. The humerus is the long bone found in the upper arm, connecting the shoulder to the elbow. The radius and ulna are the two bones of the forearm. The radius is located on the thumb side and is typically involved in wrist movement, while the ulna is on the opposite side and helps form the elbow joint. Together, these three bones facilitate a wide range of movements of the arm, including lifting, twisting, and pushing, by serving as attachment points for muscles and allowing for articulation at the joints.

The other options refer to bones that belong to different parts of the body. The femur, tibia, and fibula are bones of the lower leg; the sternum and scapula are associated with the chest, and the clavicle and pelvis pertain to the shoulder area and the lower body, respectively. Each option identifies bones integral to different bodily functions or limbs, distinct from the arm structure.