This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Gynaecology & Obstetrics
[{'content': 'Oligohydramnios is seen in all except: \nSelect and explain. \nA. Renal agenesis, B. Rh incompatibility, C. IUGR, D. Postrnaturity', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Rh incompatibility', 'role': 'assistant'}]