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: ENT
Epiglottitis in a 2-year-old child occurs most commonly due to infection with: 
Select and explain. 
A. Influenza virus, B. Staphylococcus aureus, C. Haemophilus influenzae, D. Respiratory syncytial virus
C: Haemophilus influenzae
Answer: C: Haemophilus influenzae 
Explanation: Though the introduction of Hib vaccine has reduced the annual incidence of acute epiglottitis but still most of the pediatric cases seen today are due to haemophilus influenzae B. --Harrison 17th/ed p212 In adults it can be caused by group A streptococcus, S. pneumoniae, S. aureus and Klebsiella pneumoniae