Answer:
Oxytocin
Step-by-step explanation:
Oxytocin stimulate(s) uterine contractions, cause(s) the breasts to "let down" milk, induce(s) a relaxed mood, and promote(s) responsiveness to the baby.
Oxytocin is a hormone secreted by the posterior pituitary gland and its two major functions are; the contraction of the womb (uterus) during childbirth and lactation (milk secretion/let down.