Correct Option (b) Sweat - Thermoregulation
Explanation:
Sweat glands are coiled tubular glands situated in the dermis and connected to a sweat duct which open as pore on the surface of the skin. These secrete sweat which contains 0.1 - 0.4% of sodium chloride, sodium acetate and urea.
Sweating occurs when the body temperature increases. As sweat evaporates from the skin surface, energy is lost from the body as latent heat of vaporation and in this way sweat reduces body temperature.
