Progesterone peaks in the luteal phase after ovulation

Steps:

• Recall menstrual cycle phases: follicular (days 1-14) with rising FSH/estrogen; ovulation around day 14; luteal (days 15-28) with rising progesterone.
• Identify ovulation marker: LH surge mid-cycle triggers it.
• Locate post-ovulation rise: progesterone increases sharply after LH peak to maintain uterine lining.
• Match curve: select the one low early, rising after day 14, peaking mid-luteal, then dropping.

Why B is correct:

• Progesterone, produced by corpus luteum, rises post-ovulation per hormonal feedback in luteal phase.

Why the others are wrong:

• A matches FSH: early follicular rise for follicle development.
• C matches LH: mid-cycle surge for ovulation.
• D matches estrogen: gradual follicular rise with pre-ovulation peak.

Final answer: B