An acute,contagious respiratory infection caused by a virus is:

A) tuberculosis.
B) influenza.
C) pertussis.
D) epistaxis.

Influenza

A viral infection that attacks the respiratory system, commonly known as the flu.

Respiratory Infection

An infection of the lungs, throat, or sinuses, often caused by bacteria, viruses, or fungi, leading to symptoms such as coughing, sneezing, and shortness of breath.

Virus

A microorganism that can only replicate inside the living cells of an organism and is capable of causing disease.