Answer:
I would say B: Calderas.
Explanation:
Calderas are depressions in the earth that have been made after a volcano erupts and then collapses. While Mountains could be an answer but Calderas makes more sence
Population density is a measurement of population per unit area, or exceptionally unit volume; it is a quantity of type number density. It is frequently applied to living organisms, most of the time to humans. It is a key geographical term. Hope this answered your question
Rain forest preservation, and recyciling for sure. there might be others...
The Gulf of Mexico and the Atlantic Ocean