Answer:
The author most likely includes this supporting text to reinforce the case study's point that bird flu is dangerous.
Step-by-step explanation:
The book "When Birds Get Flu" by John DiConsiglio delves into real cases of how people contract the bird flu. The book discusses infection cases and how avian influenza or bird flu began in Washington.
In the statement from the book, the author remarks that "one or two sick chickens could infect a whole town [which could in turn] infect the country—or even the world." By emphasizing the seriousness and infection level of the flu, John DiConsiglio seems to reinforce the dangerousness of the bird flu.
Thus, the correct answer is the first option.