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': 'You started a patient on oral warfarin. Which of the following factors show the most rapid decline in the blood levels after the initiation of warfarin therapy ? \nSelect and explain. \nA. Factor VII, B. Protein C, C. Factor X, D. Prod-iron-Win', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]