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': 'A person presents with headache, fever, stiff neck. Most likely organism responsible is \nSelect and explain. \nA. S.Aureus, B. Listeria, C. S.agalactiae, D. S.pneumoniae', 'role': 'user'}, {'content': 'Answer: D \nExplanation: It is case of meningitis. M/c organism responsible for meningitis is S.pneumoniae.', 'role': 'assistant'}]