This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Respiratory System, Subject name: Pediatrics
Most common cause of Bronchiolitis is: 
Select and explain. 
A. RSV, B. Adenovirus, C. Hospitalize and treat, D. Mycoplasma
A: RSV
Answer: A: RSV 
Explanation: a. RSV(Ref: Nelson's 20/e p 2044-2047, Ghai 8/e p 381-382Acute bronchiolitisIt is predominantly a viral disease and RSV is responsible for more than 50% of casesOther agents include parainfluenza, adenovirus, rhinovirus, Mycoplasma, human metapneumovirus and bocavirus.