Which part of the skeleton is made up of the skull, vertebral column, and rib cage?

The axial skeleton is composed of the skull, vertebral column, and rib cage, serving as the central core of the skeleton and providing support and protection for vital organs. The skull encases and protects the brain, the vertebral column safeguards the spinal cord, and the rib cage shields the heart and lungs. This structure not only forms the central axis of the body but also serves as an anchor point for muscles that facilitate movement and posture.

In contrast, the appendicular skeleton comprises the bones of the limbs and girdles, which are responsible for the movements of the arms and legs. The pelvic girdle specifically pertains to the bones that connect the spine to the lower limbs, while the lower extremity refers to all the bones in the leg and foot. Thus, the axial skeleton is distinctly defined and separate from these other components, making it the correct answer to the question.