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': 'Dose of Warfarin is managed by: March 2007 \nSelect and explain. \nA. INR, B. ESR, C. MAC, D. PAH', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. A: INR', 'role': 'assistant'}]