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: Dental
[{'content': 'How much iodine is required in pregnancy? \nSelect and explain. \nA. 150 mg/day, B. 250 mg/day, C. 350 mg/day, D. 450 mg/day', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]