Read the passage from The American Plague.

Monday, October 28. George Washington had been impatient since his departure from Philadelphia in early September. When he left the stricken city, he had put Secretary of War Henry Knox in charge of the government, giving the former general clear instructions to report to him weekly concerning the spread of yellow fever. But after a few days' close contact with the pestilence, Knox found that his warrior instinct had abandoned him. He closed up his house and fled across New Jersey to Manhattan Island.

What is the most likely reason the story begins with this cause-and-effect relationship?

to illustrate how cowardly Knox was
to illustrate how important the city was
to illustrate how scary yellow fever was
to illustrate how anxious Washington was