This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nutrition and Health, Subject name: Social & Preventive Medicine
[{'content': 'Calcium requirement in an infant (mg/day) - \nSelect and explain. \nA. 100, B. 200, C. 300, D. 500', 'role': 'user'}, {'content': "Answer: D \nExplanation: Ans. is 'd' i.e., 500 Calcium requirementsAgeRDA - mg/dayAdult600Pregnant1200 (+600)Lactation1200 (+600)Infant500Children 1 - 9 years60010-16 years80016-18 years800", 'role': 'assistant'}]