Answer:
All of the above.
Step-by-step explanation:
The integumentary system includes hairs, nails , skin and endocrine glands. Skin is the largest organ of the body included in the integumentary system.
The main of integumentary system is maintaining the body homeostasis by regulating the temperature regulation of the body. The integumentary system provide protection from the pathogens and excrete the harmful substance from the body. The endocrine glands synthesize and secrete various hormones of the body.
Thus, the correct answer is option (d).