The answer is D.
Melatonin is a molecule that is produced in the pineal gland and secreted into the blood. Melatonin then travels to different parts of the brain. It tells the brain and the rest of the body about the time of wake and sleep. It causes drowsiness and decreases body temperature to assist in the regulation of the sleep/wake cycle. The melatonin secretion into the blood is regulated by the endocrine system, by the hypothalamus which on gets stimulated by the light.
Answer - Well the basics and shared ancestry can be DNA & RNA as carriers of genetic info and also a universal code last be not least metabolic pathways. :)
Anticoagulation therapy and elevation of the leg
I hope this helps
