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
A person presents with headache, fever, stiff neck. Most likely organism responsible is 
Select and explain. 
A. S.Aureus, B. Listeria, C. S.agalactiae, D. S.pneumoniae
D: S.pneumoniae
Answer: D: S.pneumoniae 
Explanation: It is case of meningitis. M/c organism responsible for meningitis is S.pneumoniae.