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': 'USG at 28 weeks of gestation shows oligohydramnios is likely due to : \nSelect and explain. \nA. Gastrointestinal obstruction, B. Renal pathway obstruction, C. Anencephaly, D. Neuromuscular disorder', '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 Ref: Sheila 2e pg 216.', 'role': 'assistant'}]