Fossilization is a process that requires certain conditions so that it can take place. The climate is very important, a hot and wet place is not a place where there's a chance of finding fossils, while the places with permafrost are a much better candidate because the bacteria can not dissolve the organisms. The pressure also can play a vital role. A place that manages to keep the organisms safe from outside influence, like the tar pits, are excellent preservers. Also the structure of the organisms play a key role, a boneless organism is very hard to preserve and be fossilized, while an organism with bone structure has a bigger chance of being preserved.
A because that’s the only one that makes logically sense
Río de Janeiro in the state of Rio de Janeiro
The Amazon river flows through Peru, Bolivia, Columbia, Venezuela, Ecuador, and Brazil in South America
Western and Northern Hemispheres.