This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General obstetrics, Subject name: Gynaecology & Obstetrics
[{'content': 'Oligohydramnios is associated with : \nSelect and explain. \nA. Neural tube defects, B. Renal agenesis, C. Postmature bih, D. Premature bih', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Etiology of oligohydramnios: Intrauterine growth restriction Post-term pregnancy Premature rupture of membranes Drugs like ACE inhibitors and prostaglandin inhibitors Renal anomalies Renal Agenesis Infantile polycystic kidney disease urinary tract obstruction (refer pgno:216 Sheila 2nd edition)', 'role': 'assistant'}]