Which system includes the skin and its accessory organs, like oil and sweat glands?

The integumentary system is the correct answer as it encompasses the skin and its accessory structures, which include oil glands, sweat glands, hair, and nails. This system serves crucial functions, such as protecting the body from environmental hazards, regulating temperature, and providing sensory information. The skin acts as a barrier protecting internal organs and tissues, while the glands play key roles in hydration, thermoregulation, and maintaining skin health.

The other systems listed do not include the skin or its accessory organs. The musculoskeletal system focuses on muscles and bones, providing structure and movement. The nervous system is responsible for the transmission of signals throughout the body, primarily involving the brain, spinal cord, and nerves. The endocrine system relates to hormone production and regulation through glands, impacting various bodily functions but not directly governing the skin and its appendages. Thus, the integumentary system is uniquely positioned as the correct answer for this question.