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: Pediatrics
In a child 1 years the commonest cause of resp. Infection with wheeze is - 
Select and explain. 
A. RSV, B. Influenza viurs, C. Adenovirus, D. Para influenza
A: RSV
Answer: A: RSV 
Explanation: Ans. is 'a' i.e., RSV o Wheezing due to respiratory tract infection in a 1 year old child is due to bronchiotilis.