This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Vitamins and Nutritional Deficiencies, Subject name: Social & Preventive Medicine
[{'content': 'Which of these has the max natural source of vitamin A? \nSelect and explain. \nA. Carrot, B. Halibut liver oil, C. Cod fish oil, D. Cow milk', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Halibut Liver Oil has the maximum natural content of Vitamin A & also it has the richest source of the Vitamin D. Among fruits Ripe Mango & among vegetables carrot have high content of Vitamin A. Vitamin A deficiency causes Xerophthalmia.', 'role': 'assistant'}]