The best pyramid for this is the biomass pyramid. That is because they show how much ecological material can be found at each trophic level, which then can be used to model how the matter flows through the ecosystem that is being analyzed.
A. Canyons and sedimentary deposits
The Balkan nations are currently capitalist, not communist, so the first statement is correct. Further, they do have internal conflict, for example between the Bosniak and Serbian population in Bosnia. They also attract foreign investment.
So all the options are correct!
