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
Most common cause of acute otitis media? 
Select and explain. 
A. H. influenza, B. Strep. Pneumoniae, C. Staph aureus, D. Pseudomonas
B: Strep. Pneumoniae
Answer: B: Strep. Pneumoniae 
Explanation: The most common causative organism is Streptococcus pneumonia. Other common organisms are H. influenza and Moraxella catarrhalis. Less common causative organisms are streptococcus pyogenes, staphylococcus aureus and E.coli.Ref: PL Dhingra, Diseases of Ear, Nose & Throat, 7th edition, pg no. 67 - 68