This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: vitamins, Subject name: Biochemistry
[{'content': 'Which of the following is the major source of Vitamin D \nSelect and explain. \nA. Milk, B. Oily fish, C. Egg yolk, D. Sunlight', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Vitamin D is not strictly a vitamin since it can be synthesized in the skin, and under most conditions, this is the major source of the Vitamin D. Ref : Biochemistry by U. Satyanarayana 3rd edition Pgno : 123', 'role': 'assistant'}]