Influenza is commonly called the flu and is caused by which type of pathogen?

• A. A bacterial skin infection.
• B. A viral infection of the throat.
• C. Commonly called the flu, caused by RNA viruses that infect the respiratory tract.
• D. A chronic autoimmune disease.

Answer: (C)

Influenza is a viral infection caused by RNA viruses that infect the respiratory tract. This captures both the type of pathogen (RNA virus) and the primary site of infection (the respiratory tract), which is why it best describes influenza. It is not a bacterial skin infection, not a chronic autoimmune disease, and while it can involve the throat, the illness is defined by viral infection of the respiratory tract rather than a throat-only issue.