Read the passage from “Yellow Fever.”

About 15 percent of people who fall sick feel better for a day, but then the disease progresses to a more dangerous form. The next stage can include high fever, internal bleeding, unconsciousness, and harm to the heart, liver, and kidneys. Liver damage is like a poison, and it causes people’s skin and eyes to take on a yellow color. Yellow fever gets its name from this symptom. In the end, 20 to 50 percent of people who develop the more severe type of yellow fever die.

Which best describes why the author includes this information in the article?

to convince readers to avoid places where yellow fever occurs
to encourage readers to educate others about yellow fever
to frighten readers into getting vaccinated for yellow fever
to help readers understand the effects of yellow fever

He leaned his head against the wall; his eyes were shut, his hands clasped in each other, and his body seemed to be sustained in an upright position merely by the cellar-door against which he rested his left shoulder. the lethargy into which he was sunk seemed scarcely interrupted by my feeling his hand and his forehead. his throbbing temples and burning skin indicated a fever . . there was only one circumstance that hindered me from forming an immediate determination in what manner this person should be treated. my family consisted of my wife and a young child. our servant-maid had been seized, three days before, by the reigning malady, and, at her own request, had been conveyed to the hospital. we ourselves enjoyed good health, and were hopeful of escaping with our lives. our measures for this end had been cautiously taken and carefully adhered to. they did not consist in avoiding the receptacles of infection, for my office required me to go daily into the midst of them; nor in filling the house with the exhalations of gunpowder, vinegar, or tar. they consisted in cleanliness, reasonable exercise, and wholesome diet. who is the story’s first-person narrator