Fertility Peaks at Ovulation in Menstrual Cycle

Steps:

• Examine diagram for uterine lining thickness changes across cycle phases.
• Identify menstruation (thinnest lining), proliferative phase (thickening), ovulation (peak thickness), and secretory phase (stable then decline).
• Recognize ovulation occurs mid-cycle when lining is thickest, preparing for potential implantation.
• Determine highest fertility around ovulation due to viable egg and receptive endometrium.

Why B is correct:

• Ovulation releases the egg when the uterine lining reaches maximum thickness, creating optimal conditions for fertilization and implantation per reproductive physiology.

Why the others are wrong:

• A: Menstruation involves shedding of lining, with no viable egg present.
• C: Post-ovulation secretory phase has declining lining if no pregnancy, reducing fertility.
• D: Early proliferative phase features thin lining and immature follicle, pre-ovulation.

Final answer: B