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': 'Richest source of Vitamin D is - \nSelect and explain. \nA. Milk, B. Egg, C. Green leafy ve getables, D. Fish oil', 'role': 'user'}, {'content': "Answer: D \nExplanation: - vitamin D is unique because it is derived both from sunlight and foods. - vitamin D is necessary for the functions of bone, kidney and intestine. - the richest source of vitamin D is cod liver oil (200-750mcg per 100g) and other fish oils. Reference : Park's textbook of preventive and social medicine, 23rd edition, pg no:617 <\\p>", 'role': 'assistant'}]