Influenza is a respiratory infection caused by viruses that can be serious in older adults.

• A. It is caused by bacteria and not viruses.
• B. It is a common respiratory infection caused by viruses that can be serious in older adults.
• C. It never causes fever or sore throat.
• D. It is a chronic lung disease.

Answer: (B)

Influenza is a viral respiratory infection that can be serious in older adults. This is correct because influenza is caused by influenza viruses, not bacteria, and it commonly affects the respiratory tract. In older adults, the illness can lead to serious complications such as pneumonia or hospitalization due to age-related changes in immunity and the presence of other chronic conditions. Fever and sore throat can occur with influenza, but they are not required for the diagnosis and the disease can present with other symptoms as well. It is not a chronic lung disease, so describing influenza as chronic would be inaccurate. Recognizing its viral nature, its common respiratory involvement, and the heightened risk for older adults helps explain why this statement is true and important for prevention and management.