What structure primarily supports and protects the body’s internal organs?

The skeletal system is the correct answer because it serves as the framework for the body, providing structural support and protection for internal organs. It consists of bones, cartilage, and ligaments, which work together to form a robust structure that not only gives shape to the body but also protects vital organs such as the heart, lungs, and brain. The skull encases the brain, the ribcage shields the heart and lungs, and the spine protects the spinal cord, showcasing how the skeletal system is integral to both support and protection.

In contrast, the circulatory system is primarily responsible for transporting blood, nutrients, and oxygen throughout the body, rather than providing physical support. The muscular system plays a crucial role in movement and posture but does not function as a protective barrier for organs. The endocrine system regulates hormonal responses and influences various bodily functions, but it does not provide structural support or direct protection to the body's internal components.