Which of the following is considered the largest organ and related system of the body?

• A. Integumentary system
• B. Musculoskeletal system
• C. Nerve endings
• D. Skin

Answer: (A)

The main idea here is that the body’s outer protective layer is organized as a system that includes skin and its associated structures. The integumentary system encompasses skin, hair, nails, sweat and oil glands, and the nerves in the skin, all working together to protect the body, regulate temperature, and provide sensation. This makes it the largest organ system in terms of area and breadth of components. Since the question frames “the largest organ and related system,” identifying the integumentary system is the best answer because it includes the skin as its central component and covers all related structures. The other options point to a different system or a single organ, not the comprehensive outer-covering by which this concept is defined.