Final answer:
Oxytocin is an endocrine hormone that is produced in the hypothalamus, stored, and released by the posterior pituitary gland, particularly to stimulate uterine contractions during childbirth.
Step-by-step explanation:
Oxytocin is an endocrine hormone chiefly involved in stimulating uterine contractions during childbirth and in milk ejection during breastfeeding. It is produced by neurons in the hypothalamus and transported to the posterior pituitary gland, from where it is released into the circulatory system in response to neural signaling. Although the posterior pituitary gland does not produce hormones itself, it is responsible for storing and releasing oxytocin produced by the hypothalamus. The increase in oxytocin stimulates a positive feedback mechanism during childbirth, causing more intense contractions of the uterine wall muscles until the birth is complete. Therefore, the correct answer is (c) Posterior pituitary gland.