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: Microbiology
[{'content': 'Most common cause of SABE is: \nSelect and explain. \nA. Staph, B. Streptococcus, C. E.coli, D. Haemophilus', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Streptococcus', 'role': 'assistant'}]