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': 'Anticoagulant of choice for prophylaxis of pulmonary thromboembolism is: September 2011 \nSelect and explain. \nA. Heparan sulfate, B. Protamine sulfate, C. Low molecular weight heparin, D. Warfarin', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ans. C: Low molecular weight heparin Small fixed doses of heparin are given deep subcutaneously to prevent venous thromboembolism. LMW Heparins are prepared from native heparin.', 'role': 'assistant'}]