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: Physiology
[{'content': 'Intrinsic factor is required for absorption of ? \nSelect and explain. \nA. Folic acid, B. Vitamin B12, C. Vitamin B, D. Vitamin B2', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. is 'b' i.e., Vitamin B12", 'role': 'assistant'}]