Menstrual Cycle Hormone Peaks

Steps:

• Recall the 28-day menstrual cycle: follicular phase (days 1-14) with rising estrogen and LH surge at day 14 for ovulation.
• Identify LH peak: luteinizing hormone surges on day 14 to trigger ovulation; minor rise possible near day 28 if cycle resets.
• Identify progesterone peak: produced by corpus luteum in luteal phase (days 15-28), highest mid-luteal around days 19-23.
• Match choices to peaks: select option aligning progesterone with luteal mid-phase and LH with ovulation/end timing.

Why B is correct:

• B aligns progesterone peak (days 19-23) with mid-luteal phase production by corpus luteum and LH peaks (days 14/28) with ovulation surge and potential cycle-end rise, per standard endocrinology.

Why the others are wrong:

• A: Progesterone days 16-28 too broad, misses mid-peak; LH days 12-16 early for full surge.
• C: Day 5 and days 1-10 fall in early follicular phase when both hormones are low.
• D: Day 13 pre-ovulation (low progesterone); day 10 mid-follicular (low LH).

Final answer: B