Influenza attacks which body system?
a. digestive
b. respiratory
c. circulatory
d. lymphatic
Explanation: Influenza or flu is a virus that attacks the respiratory tract which includes the nose, throat, mouth and lungs. The flu often begins suddenly with symptoms of fever, headache, fatigue, sore throat, nasal congestion, cough and is often associated with body aches and pain. Vomiting, diarrhea and being nauseous or "sick to your stomach" can be related to influenza but are rarely the main symptom.