Just as people are affected by their enviroment, people can modify their environment in a number of ways: ...
Agriculture. People cut down forests and plow grassy plains to creat farms.
Urban Growth. People build towns and cites.
Building of Dams. ...
Energy.
The third option in here is the best option. I you see the interval, you may infer that the cross from point A to point B can not get extremely lower than 500 feet nor extremely higher than 500 feet. specially towards the middle of the way you can see that gets closer to 500 feet and towards the end you can see that amplifies and gets farther than 500 feet. The third options seem suitable
Answer:
What are you talking about???
Explanation:
What about it??