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': 'Initial treatment for pulmonary embolism is : \nSelect and explain. \nA. Fibrinolysis, B. Anticoagulation, C. Surgical embolectomy, D. Venacaval filter', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]