The African countries can easily be described and generalized, in the sense of the whole continent, as the economies are predominantly dependent on one or two products.
That dependence on one or two products is making very big problems, and it is also a very big mistake of the governments. When there's a slight variation in the prices on the certain product, the economies are heavily influenced, often in a bed manner.
It is weird though that the African countries have orientated their economies in this way, especially because the continent is very rich in lots of natural resources.
Answer: Regolith
Explanation: Regolith is formed from the constant bombardment of the lunar surface by space weathering processes, including most prominently meteoroid impacts
Personally I would say it's A (apart from the installation costs which may make it a little expensive) but it does involve certain aspects of D also as wind energy doesn't cause pollution. So either A or D!
Hope I was of help! :)
Answer:
A. the international date line