This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Miscellaneous (Obs), Subject name: Gynaecology & Obstetrics
[{'content': 'Rh isoimmunisation in which trimester \nSelect and explain. \nA. 10-12 weeks, B. 30-32 weeks, C. 36 weeks, D. Immediately after delivery', 'role': 'user'}, {'content': "Answer: B \nExplanation: (B) 30-32 weeks> Because of its short half-life, Rh IgG routinely is administered once at 28-32 weeks' gestation and again within 72 hours after birth to all Rh-negative pregnant females as a part of routine prenatal care.", 'role': 'assistant'}]