Influenza outbreaks that affect 5-20% of the united states population each year are an example of a(n) plague. pandemic. trauma. epidemic.

The appropriate answer is epidemic. The use of influenza in the paragraph fits the word epidemic. It expresses the outbreak of the disease during the same period.

Pandemic is not the right term since it tells a permanent condition. Also, trauma is a negative effect to a person who experienced bad conditions or situations. Plague is a spread out of disease that can happen anytime.