The correct option is A Corpus luteum
In the menstrual cycle.
Rapid secretion of LH leading to
its maximum level during the mid-cycle called LH surge induces rupture
of Graafian follicle and thereby the release of ovum (ovulation). The
ovulation (ovulatory phase) is followed by the luteal phase during which
the remaining parts of the Graafian follicle transform as the corpus
luteum.
Corpus callosum and secondary follicle is not formed by Graafian follicle.