Which of the following glands produces oil that lubricates hair follicles?

A. Eccrine:
Eccrine glands are sweat glands that are widely distributed across the body and primarily function in regulating body temperature through sweat production. They do not produce oil for hair follicle lubrication.

B. Ceruminous:
Ceruminous glands are specialized sweat glands located in the external ear canal. They produce earwax (cerumen. rather than oil for lubricating hair follicles.

C. Sebaceous:
Sebaceous glands produce an oily substance called sebum, which lubricates and moisturizes hair follicles and the skin. This oil helps prevent hair and skin from becoming too dry.

D. Apocrine:
Apocrine glands are sweat glands found mainly in the axillary and groin regions. They secrete a thicker sweat that is associated with body odor and does not produce oil for hair follicle lubrication.

A. Androsterone and estradiol: Androsterone and estradiol are both sex hormones, but they do not function as antagonists. Androsterone is an androgen, and estradiol is an estrogen; they have different roles in sexual development and reproductive health but do not directly oppose each other.

B. Ghrelin and gastrin: Ghrelin and gastrin are hormones involved in regulating appetite and digestion. Ghrelin stimulates hunger, while gastrin stimulates gastric acid secretion. They do not act as direct antagonists to each other.

C. Insulin and glucagon: Insulin and glucagon are hormone antagonists that regulate blood glucose levels. Insulin lowers blood glucose by facilitating its uptake into cells, while glucagon increases blood glucose by promoting glycogen breakdown in the liver. Their actions counterbalance each other to maintain glucose homeostasis.

D. Calcitonin and melatonin: Calcitonin and melatonin have distinct functions; calcitonin helps regulate calcium levels in the blood, while melatonin regulates sleep-wake cycles. They do not have antagonistic effects on each other.