You are presented with the question "Which of these produces hydropower?" and the following answer choices: 
- deuterostomes
 - Wind Turbines
 - power stations
 - Suez Canal
 - trout
 - Old Faithful Geyser
 - Hoover Dam
 - stations

Now knowing that hydropower requires damming a river and hoover Dam, the first dam on the Colorado River below Grand Canyon, was built between 1931 and 1935, choose the best answer.


 

       Hoover Dam  