Identify the hormone with its correct matching of source and function.

Melatonin secreted by pineal gland plays a very important role in the regulation of a 24-hour (diurnal) rhythm of our body. It helps in maintaining the normal rhythms of sleep-wake cycle, body temperature. 

Progesterone secreted by corpus luteum supports pregnancy. Progesterone also acts on the mammary glands and stimulates the formation of alveoli (sac-like structures which store milk) and milk secretion. Estrogens secreted by growing follicles produce wide ranging actions such as stimulation of growth and activities of female secondary sex organs, development of growing ovarian follicles, appearance of female secondary sex characters (e.g., high pitch of voice, etc.), mammary gland development. Estrogens also regulate female sexual behavior. 

Oxytocin secreted by neurohypophyses, acts on the smooth muscles of our body and stimulates their contraction. In females, it stimulates a vigorous contraction of uterus at the time of childbirth, and milk ejection from the mammary gland. 

The atrial wall of our heart secretes a very important peptide hormone called atrial natriuretic factor (ANF), which decreases blood pressure.