Answer: Positive feedback
Explanation:
Positive feedback is a process by which the end product of the action causes more action to be performed or occur in the feedback loop. This amplifies the original action.
The suckling action of milk from the breast of the mother is a positive feedback. The suckling action of milk leads to the production of prolactin. The prolactin hormone triggers the production of milk, more suckling leads to more synthesis of prolactin, which in turns leads to more lactation.