Read this excerpt from an argumentative essay:

One explanation for why the national parks are so important is that they provide many Americans with the opportunity to experience wildlife in its natural habitat. Every major city in the United States has a zoo, which is great, but how much more significant is the sight of a brown bear in its natural setting rather than in a cage? A trip to a park like Yellowstone National Park may be the only chance a youngster from a place like New York City or Chicago will have to behold such a sight. If we, the American people, were to lose places like Yellowstone, it would be a travesty.

Where in an argumentative essay does this excerpt belong?