This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Respiratory system, Subject name: Medicine
[{'content': 'Prophylactic measure DVT includes - \nSelect and explain. \nA. Warfarin, B. Heparin, C. Graduated elatic compression stocking, D. All of the above', 'role': 'user'}, {'content': "Answer: D \nExplanation: Heparin anticoagulates by binding to and accelerating the activity of antithrombin,thus preventing additional thrombus formation and permitting endogenous fibrinolytic mechanisms to lyse clot that already has formed.Warfarin is a vitamin K antagonist that prevents carboxylation activation of coagulation factors 2,7,9,10.Daily use of below-knee 30 to 40 mmHg vascular compression stockings also act as a prophylactic measure for DVT. Reference:Harrison's medicine:18th edition,page no:2175", 'role': 'assistant'}]