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': 'Thrombolytics can provide relative mortality reduction in the treatment of acute myocardial infarction, if patient comes within : \nSelect and explain. \nA. 6 hours, B. 12 hours, C. 18 hours, D. 24 hours', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]