Which of the following is a function of the integumentary system?

The integumentary system is primarily composed of the skin and its associated structures, such as hair, nails, and glands. One of its most vital functions is providing protection against environmental hazards. This includes acting as a physical barrier that shields the underlying tissues and organs from pathogens, chemicals, and physical damage. The skin also helps to protect against UV radiation and dehydration, thus maintaining the integrity of the body's internal environment.

In addition to protection, the integumentary system plays a role in sensation, thermoregulation, and excretion, but the function of protection is the most prominent one associated with this system. While other systems in the body are responsible for movement, hormone production, and fluid regulation, these are not primary functions of the integumentary system, allowing us to clearly identify protection as its crucial role.