What sentence best supports the staternent that hormones are involved in the regulation of homeostasas? The hormone melatonin induces sleep and its production is slowed by exposure to light. The hormone cortisol suppresses the immune system and is produced when the body is under stress. The hormone oxytocin promotes labor contractions of the uterus during childbirth. The hormone erythropoeitin increases the production of red blood cells when oxygen levels are low.