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: Unknown
[{'content': 'External cephalic version is now a days done at - \nSelect and explain. \nA. 34 weeks, B. 36weeks, C. 38 weeks, D. 40 weeks', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans: B', 'role': 'assistant'}]