Step 1: Recall the correct associations for each entity.
• Asherman syndrome = intrauterine (endometrial) synechiae/adhesions, classically after vigorous post-partum or post-abortal dilatation and curettage; an outflow/uterine (end-organ) cause of secondary amenorrhoea with normal hormones.
• PCOD = chronic anovulation with high/normal LH, raised LH:FSH ratio and hyperandrogenism - NOT hypogonadotropic with low LH.
• Sheehan syndrome = post-partum pituitary necrosis to hypogonadotropic hypogonadism (low FSH/LH), not primary ovarian failure.
• POF (premature ovarian insufficiency) = hypergonadotropic hypogonadism with high FSH due to ovarian failure, not an outflow obstruction.
Step 2: Test each option against these facts. Only option 1 is internally correct: Asherman = intrauterine adhesions from endometrial scarring. Options 2, 3 and 4 each pair the condition with the WRONG mechanism (PCOD is not low-LH hypogonadotropic; Sheehan is pituitary, not ovarian; POF has high FSH, not outflow obstruction).
Key fact: Asherman syndrome to intrauterine adhesions; Sheehan to pituitary (low gonadotropins); POF to high FSH ovarian failure; PCOD to high LH:FSH anovulation.