Some Challenges in the tropical rainforest is that Deforestation is common and its really bad because they're limiting the rainforest size just to build homes and towns. Basically, Just forgetting about the habitats and the animals and the other tribes.
This movement is called convection. It can be found in liquids, gasses and rheids - solids that can also experience movement ( on a big time scale), such as the earth mantle. One of the types of convection is diffusion: net movement of gasses from higher to lower concentration areas.
During the medieval era the Catholic Church became a more elaborate heirachy. The pope became an image of of supreme power in Europe. There was also a large population growth. Towns and cities wanted more self control. This caused a political and social struggle.
This struggle caused a huge demand of a more direct experience with Christ. Christ and his apostles became an image of more radical simplicity. The church became made a huge impact in daily life. It served as a spiritual and religious guidance. The church also made an impact into Europe's government.
Speaking from experience, the answer is not D.
I think Mount Elbrus is the highest point in Europe.
