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: Pathology
[{'content': 'Hemophilia A is caused due to deficiency of \nSelect and explain. \nA. Factor X, B. Factor XI, C. Factor IX, D. Factor VIII', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]