The corpus luteum is
a. the ruptured follicle following the ejection of an oocyte from the ovary part of the uterine tube
b. the mesovarium
c. the ovarian ligament that anchors the ovary medially to the uterus

a. the ruptured follicle following the ejection of an oocyte from the ovary part of the uterine tube

Explanation:

Ovulation (the release of eggs from the ovaries) occurs when the ovary wall ruptures and expels the secondary oocyte. After ovulation the ruptured follicle collapses, then the  granulosa cells in turns enlarge along with internal thecal cells (a group of endocrine cells in the ovary), these structure forms the corpus luteum .

The corpus luteum helps to  secrete progesterone and estrogen . If pregnancy does occur, the corpus luteum produces hormones until the placenta takes over that role for about 3 months. If pregnancy does not occur, the corpus luteum degenerates in 10 days.

i would go with b

cytokinesis occurs after telophase so that eliminates d

and the entire reason for cytokinesis is for cellular reproduction

the median of the data is 4.5.