A 4-Year-Old Girl Is Brought to Your Rural Clinic Office

A 4-year-old girl is brought to your rural clinic office by her mother who states the child has a runny nose, barking cough, and a sore throat. Your examination indicates respiration is labored. None of her three siblings is sick. The most probable viral cause of her symptoms is

A) Adenovirus
B) Influenza virus
C) Parainfluenza virus
D) RSV