Read the passage from When Birds Get the Flu by John DiConsiglio.

The deadliest pandemic of the last 100 years was the Spanish flu. It started in the fall of 1918. World War I was ending. Tired soldiers were returning to their homes. No one imagined that another enemy was about to attack.

Which excerpt from the passage most belongs in the body of an essay supporting the claim that scientists should continue to study the Spanish flu?

The deadliest pandemic of the last 100 years was the Spanish flu.
It started in the fall of 1918. World War I was ending.
Tired soldiers were returning to their homes.
No one imagined that another enemy was about to attack.