Read the excerpt below from a florida government land-use study and answer the question that follows. in it, the authors describe how humans need to recognize themselves as part of the ecosystem in which they live.

from a biological perspective, modern cities and suburbs resemble the noisy, crowded bird colonies scattered on offshore islands and rocky coastlands across the globe. in the animal kingdom, colonies are a fairly sustainable way of life, providing two basic conditions are met. first, colonies can persist, even thrive, if the demand for resources by the inhabitants does not exceed the supply readily available from surrounding areas. second, colonies can be sustained if the waste they produce does not poison its inhabitants.

like bird colonies, cities and suburbs draw heavily on the resources of the surrounding environment. what was once a relatively small stream of resources flowing into early cities, however, has in this century become a deluge. to satisfy resource-hungry human colonies, land is often stripped bare, trampled, or overgrazed, soil is subjected to erosion, a farmland is transformed into desert. cities and suburbs also produce sizable amounts of waste. air pollution, hazardous waste, sewage sludge, garbage, and other wastes pour out of our cities. .

the problem with human colonies is that they violate the conditions required for sustainability. metropolitan areas are out of balance with the environment upon which they depend. . the ever persistent spread of cities will continue to devour valuable farmland, forests, and pasture. gobbling up land and polluting the water and air upon which all life depends, our cities are on a collision course with the future.

which word best describes the overall tone of the excerpt?

a.
humorous
b.
educational
c.
warning
d.
despairing