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: Pharmacology
[{'content': 'Vitamin K dependent clotting factors are : \nSelect and explain. \nA. Factor IX and X, B. Factor IV, C. Factor XII, D. Factor I', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]