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': 'Factor X is ? \nSelect and explain. \nA. Hageman factor, B. Stua-Prower factor, C. Christmas factor, D. Tissue factor', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. is 'B' i.e., Stua-Prower factor", 'role': 'assistant'}]