During the first stage of the menstrual cycle, the estrogen hormone stimulates the maturation of ovarian follicles. In the second menstrual stage, ovulation, high levels of estrogen cause the ovaries to release the matured ovum into the fallopian tubes for fertilization. What two body systems work together to produce and release the ovum? O A. ' circulatory and reproductive systems O B. circulatory and lymphatic systems OC. endocrine and reproductive systems OD. endocrine and lymphatic systems