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: Medicine
[{'content': 'Subdural empyema is most commonly caused by - \nSelect and explain. \nA. H. influenzae, B. Staphylococus aureus, C. Streptococcus pneumoniae, D. E. Coli', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]