Final answer:
The hormone responsible for the formation of the corpus luteum from the ruptured follicle is the Luteinizing hormone (LH).
Step-by-step explanation:
The formation of the corpus luteum from the ruptured follicle is regulated by Luteinizing hormone (LH). Following ovulation, the ovarian cycle enters the luteal phase, during which the surge of LH stimulates a change in the granulosa and theca cells that remain after the oocyte has been ovulated. This process, known as luteinization, transforms the collapsed follicle into the corpus luteum, which begins to produce large amounts of the hormone progesterone. Progesterone is critical for the establishment and maintenance of pregnancy and triggers negative feedback at the hypothalamus and pituitary to keep GnRH, LH, and FSH secretions low, preventing the development of new dominant follicles at this time.