This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Cardiovascular system, Subject name: Physiology
[{'content': 'All are Vitamin K dependent clotting factors \nSelect and explain. \nA. Factor II, B. Protein C, C. Factor X, D. Factor IX', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Vitamin K is required for the synthesis of factor 2,7,9, and 10 by the liver.Ref: Textbook of medical physiology by N Geetha, 2nd edition, page no. 107', 'role': 'assistant'}]