Final answer:
The hormones estrogen and progesterone are responsible for regulating the menstrual cycle, pregnancy, and lactation in females. They work in conjunction with hormones such as FSH and LH from the pituitary gland and others like prolactin and oxytocin which are involved in lactation. The correct answer to the question is A
Step-by-step explanation:
The female sex hormones responsible for the menstrual cycle, pregnancy, and lactation are estrogen and progesterone. These hormones regulate the various aspects of the female reproductive cycle through a complex hormonal interplay.
The menstrual cycle is governed by fluctuating levels of these hormones, which is further modulated by other hormones such as Follicle-Stimulating Hormone (FSH) and Luteinizing Hormone (LH) produced by the pituitary gland, as well as Prolactin and Oxytocin which are involved in lactation.
Specifically, estrogen is vital for endometrial regrowth, ovulation, and maintaining secondary sexual characteristics. Progesterone plays roles in endometrial re-growth and moderation of FSH and LH release.
During pregnancy, estrogen and progesterone levels increase significantly to maintain the endometrium and suppress further ovulatory cycles. After childbirth, prolactin promotes lactation, while the role of oxytocin is in the let-down reflex of milk secretion.