Which parts make up the appendicular skeleton?

The appendicular skeleton consists of the bones that make up the limbs and the girdles connecting them to the axial skeleton. Specifically, it includes the shoulder girdle (which comprises the clavicle and scapula), the pelvic girdle (which forms the base of the spine and connects the lower limbs), and the bones of the arms (humerus, radius, and ulna) and legs (femur, tibia, and fibula). This structure is essential for mobility and manipulation.

The other options do not fully encompass the components of the appendicular skeleton. The skull and spine, for instance, are part of the axial skeleton, which serves as the central framework of the body. The rib cage and arms mention bones in the upper body but miss key elements of the pelvic girdle and the legs. Hands and backbone again focus on parts of the upper body but neglect the legs and hips entirely. In summary, the defining components of the appendicular skeleton clearly include the shoulder, pelvic girdles, arms, and legs.