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: Surgery
[{'content': 'All are done for a case of deep vein thrombosis except- \nSelect and explain. \nA. Thrombolytic therapy, B. Bandage, C. Heparin, D. Bed rest', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Immobilization is a risk factor for DVT.', 'role': 'assistant'}]