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
Which of the following is the commonest etiological agent of Bronchiolitis ? 
Select and explain. 
A. HCV, B. HSV, C. RSVH, D. Influenza virus
C: RSVH
Answer: C: RSVH 
Explanation: Description: Bronchiolitis refers to inflammation of the bronchioles. It is commonly found in infants and children and is caused by respiratory syncitial virus or adenovirus. Children presents with insidious onset of cough and dyspnea. PFT shows irreversible airflow obstruction.