Step 1: Define the clinical task. A 21-year-old with a 10-week (first-trimester, ≤ 9-10 weeks) pregnancy is to have a MEDICAL (drug-induced) termination of pregnancy. We must choose the standard medical-abortion regimen for early pregnancy.
Step 2: Recall the recommended regimen. The WHO/FOGSI-endorsed first-line medical abortion regimen up to 9-10 weeks is the combination of Mifepristone followed by Misoprostol - i.e. M + M. Mifepristone is an antiprogesterone that detaches the pregnancy and sensitises the uterus, and misoprostol (a prostaglandin E1 analogue) given 24-48 hours later induces uterine contractions and expulsion. This is the most effective and standard medical method for first-trimester MTP.
Step 3: Eliminate the distractors.
• Intra-uterine hyperosmotics (A) (e.g. intra-amniotic hypertonic saline / urea) are used for SECOND-trimester instillation abortion, not for a 10-week pregnancy.
• Dinoprostone (B) is prostaglandin E2, used mainly for cervical ripening / second-trimester termination and labour induction, not as the standard first-trimester medical abortion drug.
• Oxytocin infusion (C) is ineffective for first-trimester abortion because the early uterus has very few oxytocin receptors; oxytocin is used in later pregnancy/labour.
Step 4: Conclude. For a 10-week medical MTP the regimen is mifepristone plus misoprostol (M + M).
Final answer: D - M + M.