This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Ear, Subject name: ENT
[{'content': 'Commonest cause of otogenic meningitis is: \nSelect and explain. \nA. Streptococcus pneumoniae, B. H. influenza, C. Pseudomonas, D. E. coli', 'role': 'user'}, {'content': 'Answer: A \nExplanation: (a) Streptococcus pneumoniae(Ref. Cummings, 6th ed., 2171)MC cause of otogenic meningitis was H. influenzae but after the introduction of Hib vaccine in the universal immunisation programme, it is Streptococcus pneumoniae now.', 'role': 'assistant'}]