• Prolactin is secreted by the anterior pituitary (A → V).
• Progesterone is produced mainly by the corpus luteum after ovulation (B → III).
• Melatonin is secreted by the pineal gland (C → I).
• Calcitonin is produced by the parafollicular C-cells of the thyroid gland (D → II).
• Therefore the correct matching is (4) A-V, B-III, C-I, D-II.