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: Biochemistry
[{'content': 'Which Fat soluble vitamin is functioning like a "Hormone": \nSelect and explain. \nA. Vitamin A, B. Vitamin D, C. Vitamin E, D. Vitamin K', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Vitamin D', 'role': 'assistant'}]