A new mother who is breastfeeding asks the nurse what triggers the transition from colostrum to mature milk. The nurse correctly responds:

"Lactogenesis II occurs after the delivery of the placenta which triggers a drop in progesterone and triggers milk production.”.

"Lactogenesis I occurs once the fetus is delivered.”.

"Lactogenesis III causes milk stasis.”.

"Lactogenesis II begins once your uterus has involuted.”. . . .