Answer: A . the history of the Hoover Dam and its impact on the Southwest region.
Step-by-step explanation:
This question is based on the article, ''The Hoover Dam'' by Michael Stahl. In it the author begins by describing what hydroelectricity is and how it came about.
The author then used the Hoover Dam to illustrate the points made about hydroelectricity by first giving a brief history of the construction of the dam and the sacrifices it took to build it. The impact the dam had on the area it supplies - the Southwest - was also analysed.