The reproductive cycle in females is regulated primarily by

The correct answer is estrogen and progesterone.

Explanation:

The primary female sex hormone known as estrogen is accountable for the directive and development of the female reproductive system and secondary sex features. The other essential hormone apart from estrogen is progesterone, it takes part in pregnancy, menstrual cycle, and embryogenesis.  

Both estrogen and progesterone work in synchronized manner to encourage reproductive activity of the female comprising the development and upkeep of the corpus luteum to withstand a fertilized ovum, development of the ovum, preparation of the breasts for lactation, and maintenance of pregnancy.