Which choice correctly describes the Graafian follicle?

The Graafian follicle is indeed enlarged by follicle stimulating hormone (FSH). During the ovarian cycle, FSH stimulates the growth and maturation of the ovarian follicles, and the Graafian follicle represents a mature follicle that is on the verge of ovulation. As these follicles develop, they increase in size due to the proliferation of granulosal cells and the accumulation of fluid, leading to the formation of an antrum.

While other choices contain elements of truth, they do not encapsulate the primary role and definition of the Graafian follicle as precisely as the correct choice. The Graafian follicle is not primarily a site of hormone production (though it does produce some hormones), nor is it correct to say it is the structure that releases eggs during ovulation (as it is the mature follicle that eventually does release the egg during the ovulation phase). After ovulation, the Graafian follicle does transform into the corpus luteum, but this depiction does not focus on the follicle's development stage prior to ovulation. Thus, the statement about its enlargement due to follicle stimulating hormone accurately reflects its biological significance.