Q.Mature Graafian follicle is generally present in the ovary of a healthy human female around:

The menstrual cycle in a healthy human female averages 28 days and is divided into distinct phases. The follicular phase begins on day 1 (onset of menstruation) and continues until ovulation, during which several primary follicles in the ovary start developing under the influence of FSH (follicle-stimulating hormone).

One of these follicles grows faster than the others and becomes the dominant follicle. By around day 13–14 of the cycle, this dominant follicle matures into a Graafian follicle — a large, fluid-filled structure ready to release its secondary oocyte. The Graafian follicle is characterized by a well-developed antrum and is the final stage before ovulation occurs (typically on day 14 in a 28-day cycle).

Looking at the options:

• Days 5–8 are early follicular phase; follicles are still developing. …

The menstrual cycle is a precisely timed sequence of events in the ovary and uterus, orchestrated by hormones. To understand when the Graafian follicle matures, we need to trace the journey of a follicle from its resting state to the moment it releases an egg.

The cycle begins on day 1 with menstruation. Simultaneously, in the ovary, several primary follicles are recruited to begin growing under the influence of FSH (follicle-stimulating hormone) secreted by the pituitary gland. This marks the start of the follicular phase or proliferative phase, which typically lasts from day 1 to day 13–14 of a standard 28-day cycle.

During the first week (days 1–7), these follicles are still small, developing through primary and secondary stages. By days 5–8, they have not yet reached the tertiary or Graafian stage—they are still maturing, accumulating fluid in the antrum, and the oocyte inside is preparing for its final growth spurt.

The real transformation happens in the second week. Around days 8–12, one follicle becomes dominant—it grows faster than the others, which regress. This dominant follicle continues to enlarge, its antral cavity fills with follicular fluid, and the layers of granulosa and theca cells proliferate. By days 11–14, this follicle has become a mature Graafian follicle—a large, fluid-filled structure bulging at the surface of the ovary, ready to rupture.