Starting from puberty, monthly changes in ovaries and uterus also starts. The layer of cells surrounding primary oocyte are called granulosa cells and together, they are called primary follicle. The growth of the follicles is under the influence of pituitary hormones FSH and LH. Further growth is also stimulated by estrogen. The mature Graafian follicle is present in the ovary around 11−17 day of menstrual cycle and on rupture of which, ovum is released (because of LH surge, 1−2 days before ovulation). So, the correct answer is '11−17 day of menstrual cycle'.