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: Social & Preventive Medicine
[{'content': 'The daily extra calorie requirement in first trimester of pregnancy is \nSelect and explain. \nA. 50, B. 150, C. 350, D. 450', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]