The correct option is C A- Primary follicle, B- Graafian follicle , C- Secondary oocyte
The diagram given in the question depicts the various stages of follicular development and the formation of corpus luteum in an ovary.
The different parts can be labelled as:
A-Primary follicle, it is an immature ovarian follicle surrounded by a single layer of cuboidal cells called granulosa cells.
B-Graafian follicle, it is a fully developed, mature follicle which contains the secondary oocyte.
C- Secondary oocyte. It divides and forms the ovum on coming in contact with the sperm.