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

The Spanish flu would kill between 40 and 50 million people—more people [than] were killed in the war.

This pandemic affected everyone—and spread everywhere. Outbreaks swept through North America, Europe, Asia, Africa, Brazil, and the South Pacific. At one point, one-fifth of the entire globe was infected. . . .

So where did this killer flu come from? In 2005, researchers at the CDC announced that it had probably started off as a bird flu and then jumped to humans.

The author most likely includes this evidence to support the conclusion that

the Spanish flu was a worldwide epidemic.
another worldwide flu like the Spanish flu is possible.
another flu like the Spanish flu is spreading worldwide.
the worldwide effects of the Spanish flu had consequences.