The integumentary system, which is the largest organ system of the human body, is made up of skin, hair, nails and glands. The respiratory system is composed of the respiratory tract and the lungs. How do the integumentary and respiratory systems work together to protect the human body?

A. The two systems allow for the storage of nutrients to fuel the body at a later time.

B. The two systems deliver signals between the outside environment and the brain.

C. The hair and mucus that line the respiratory tract prevent foreign particles from entering the body.

D. The immune cells send electrical signals through the skin to the brain.