Which action is NOT a function of the musculoskeletal system?

The musculoskeletal system comprises bones, muscles, tendons, ligaments, and cartilage, which work together to support the body, enable movement, and protect vital organs. While options A, B, and D accurately reflect the roles of this system—protection of internal organs, enabling mobility, and providing structural shape—option C refers to hormone production, which is primarily the function of the endocrine system. Hormones are produced by specific glands such as the pituitary, thyroid, adrenal, and pancreas, and they play vital roles in regulating various bodily functions, including metabolism and growth, but are not produced by components of the musculoskeletal system. Therefore, the action that is not a function of the musculoskeletal system is indeed the production of hormones.