What factors are resulting in a decrease in population in the region of southern europe

The region of Southern Europe, because of its proximity to the Mediterranean Sea, enjoys a Mediterranean climate. The area is fairly mild and wet in the winter and can be very hot and dry in the summer (Fisher, 1992, p.203). The coastal areas are at or near sea level elevations, but within the countries there are several highlands and mountain chains. In Italy, the Apennine Mountains run the span of the country from north to south. The Alps run east and west, along the northern Italian border with Switzerland. In Spain, the Pyrenees Mountains run north and south along the Spanish-French border. In Greece, we find the famous Mount Olympus and the Pindus Mountains.

answer; i believe the correct answer is (a) nigeria is the largest african crude (oil) supplier; /// so revenue from petroleum;