The answer is D. Exosphere
Exosphere is the outermost Layer of the Atmosphere that goes out about 500 - 10,000 Km in altitude.
It's the place where satellites and the space shuttle orbit the earth. Because it's difficult to define the boundary between exosphere and the outer space, exosphere may be considered as a part of outer space
Water and wind because they can shape different natural feautures. So water
A dome mountain is formed
Answer:
It would be important for the boys to know the geography of the area so that they don't get lost and if they did, they would be able to find their way back.