Which system gives the body its general shape, provides structural support, and protects internal organs?

The musculoskeletal system is the correct choice because it encompasses both the bones and muscles in the body, which work together to provide structural support, maintain posture, and give the body its overall shape. The bones, as part of this system, form the skeleton, which not only defines the body's structure but also serves to protect vital internal organs—from the rib cage shielding the heart and lungs to the skull safeguarding the brain.

Moreover, the musculoskeletal system enables movement through the connection between muscles and bones, facilitating a wide range of physical activities essential for everyday functioning. This dynamic interaction between bones and muscles is critical for not just maintaining physical integrity but also for performing movements effectively.

In contrast, the nervous system is mainly involved in transmitting signals and processing information, the circulatory system focuses on the transport of blood and nutrients, and the endocrine system regulates hormones and metabolic functions. Each of these systems has important roles in the body, but they do not provide the same foundational structure and protective roles that the musculoskeletal system does.