Arrange the given events of menstrual cycle in correct sequence.A. In…

The correct answer is Option (2) → B, D, C, A

Note: The given answer is as per the official NTA Answer Key. However, none of the given options appears to be correct. According to NCERT the correct sequence is B, A, D, C, which is not given in any option, as explained below.

(B) Enhanced level of FSH — this comes first. FSH from the pituitary gland acts on the ovary and stimulates the growth of the follicles.

(A) Increased level of estrogen — this comes second. The growing follicles secrete estrogen, and its level rises gradually in the follicular phase.

(D) Rapid secretion of LH — this comes third. The estrogen level is then high. LH is released rapidly and reaches its peak in the middle of the cycle. This LH surge makes the Graafian follicle burst and release the ovum (ovulation).

(C) Increased level of progesterone — this comes last. After ovulation, the remains of the follicle become the corpus luteum, which secretes a large amount of progesterone.

Option (2) puts the rise in estrogen at the end, and Option (3) puts the LH surge before it. But NCERT describes the rise in estrogen in the follicular phase, before the LH surge, so no option matches it.

NCERT Extract:
Menstrual Cycle – “… These changes in the ovary and the uterus are induced by changes in the levels of pituitary and ovarian hormones (Figure 2.9). The secretion of gonadotropins (LH and FSH) increases gradually during the follicular phase, and stimulates follicular development as well as secretion of estrogens by the growing follicles. Both LH and FSH attain a peak level in the middle of cycle (about 14th day). Rapid secretion of LH leading to its maximum level during the mid-cycle called LH surge induces rupture of Graafian follicle and thereby the release of ovum (ovulation).”
Menstrual Cycle – “… The corpus luteum secretes large amounts of progesterone which is essential for maintenance of the endometrium.”