Answer:
A. all of the answer choices
Step-by-step explanation:
one reason why the influenza epidemic was such a problem was because it was contained poorly. people had it before they knew about it and then would accidentally spread it to others. the soldiers were in constant contact with others and some lived in poor conditions, this helped spread the virus quickly among them and then when they would go home they then gave it to others. the virus spread quickly and would infect people in close contact with people infected.