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: Unknown
[{'content': 'Which vitamin is found as a constituent of Warburg yellow enzyme - \nSelect and explain. \nA. B1, B. B2, C. Niacin, D. Pantothen acid', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans-B', 'role': 'assistant'}]