Answer: B) to inform readers about the multiple uses of GIS.
Explanation: when writing, an author can have several different purposes, for example: to inform, to entertain, to persuade, to criticize, etc. In the given excerpt from the article "What Is GIS?" we can see that the writer describes some of the multiple uses of GIS (like making cartographic models, or hypothetical research models that mimic natural ecological systems, etc). So the correct answer is option B: the purpose of the excerpt is to inform readers about the multiple uses of GIS.
