What is the function of the axial skeleton?

The function of the axial skeleton primarily centers around its role in protecting vital organ systems, which is why this is the correct choice. The axial skeleton includes the skull, vertebral column, and rib cage, all of which play critical roles in encasing and safeguarding essential organs. For instance, the skull protects the brain; the vertebrae form a protective column around the spinal cord; and the rib cage shields the heart and lungs.

While the other choices address important aspects of the skeletal system, they do not accurately represent the primary function of the axial skeleton. For instance, aiding in locomotion pertains more to the appendicular skeleton, which comprises the limbs and girdles that facilitate movement. Supporting muscle attachment is a function seen throughout both the axial and appendicular skeletons, but the axial skeleton is not primarily known for this role. Hormonal balance is unrelated to the mechanical or protective functions of the skeletal system altogether. Thus, the emphasis on protecting vital organs highlights the essential role the axial skeleton plays in maintaining the body's structural integrity and organ safety.