During which phase of the ovarian cycle does the leftover follicle, from which the ovum was released, develop into the corpus luteum?

Postovulatory

Menstrual

Preovulatory

The answer is postovulatory.

The postovulatory phase is also known as Luteal phase because of the corpus luteum which develops from the leftover follicle. As the name suggests, the postovulatory phase occurs after ovulation. In the ovulation phase, an egg (ovum) is released from ovaries. In the postovulatory phase, leftover follicle transforms into the corpus luteum which can end up in either degradation or pregnancy.