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 requirement of Vitamin D in infants and children is \nSelect and explain. \nA. 2.5 mcg (100 IU), B. 10.0 mcg (400 IU), C. 5.0 mcg (200 IU), D. 20.0 mcg (800 IU)', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]