C. Nuclear to be honest, I don’t know, but I think this is the answer.
Answer:
Hydrosphere: all the waters on the earth's surface, such as lakes and seas, and sometimes including water over the earth's surface, such as clouds.
Biosphere: the regions of the surface, atmosphere, and hydrosphere of the earth (or analogous parts of other planets) occupied by living organisms.
Geosphere: any of the almost spherical concentric regions of matter that make up the earth and its atmosphere, as the lithosphere and hydrosphere.
Atmosphere: the envelope of gases surrounding the earth or another planet.
I don't know if that will help but hopefully it does
Explanation:
One cause is immigration. There is a lot of people immigrating to from other countries to the US. This has caused the population in the US to increase
