A) option is correct
Step-by-step explanation:
Skin has two types of sweat glands: eccrine and apocrine
Eccrine glands occur over most of the body and open directly onto the surface of skin whereas apocrine glands open into the hair follicle, leading to the surface of the skin and develop in areas abundant in hair follicles, such as on scalp, armpits and groin
The eccrine gland is controlled by the sympathetic nervous system and regulates body temperature
In some animals, when internal temperature rises the eccrine glands secrete water to the skin surface, where heat is removed by evaporation
Eccrine glands when active are considered major thermoregulatory devices
Smaller mammals, such as rodents, cannot endure dehydration and hence possess no eccrine glands at all