Oxytocin is the hormone responsible for milk ejection.
Correct AnswerB. Oxytocin
Hormone Roles
Prolactin (A) stimulates milk production in mammary glands.
Oxytocin (B) triggers milk ejection (letdown reflex) via smooth muscle contraction around ducts.
Estrogen (C) and Progesterone (D) support mammary gland development during pregnancy.