The best and most correct answer among the choices provided by the question is the third choice "natural monopolies"
Natural monopolies<span> arise where the largest supplier in an industry, often the first supplier in a market, has an overwhelming cost advantage over other actual or potential competitors; this tends to be the case in industries where fixed costs predominate.</span>
I hope my answer has come to your help. God bless and have a nice day ahead!
I think it would be trains and railroads. otherwise you walk or use a horse
Prussia’s defeat of Austria in the Seven Weeks’ War in 1866 had confirmed Prussian leadership of the German states and threatened France’s position as the dominant power in Europe. The immediate cause of the Franco-German War, however, was the candidacy of Prince Leopold of Hohenzollern-Sigmaringen (who was related to the Prussian royal house) for the Spanish throne, which had been left vacant when Queen Isabella II had been deposed in 1868. The Prussian chancellor, Otto von Bismarck, and Spain’s de facto leader, Juan Prim, persuaded the reluctant Leopold to accept the Spanish throne in June 1870.
D: Djenn'e-Djeno. Songhai collapsed, Mali fell to Songhai, and Ghana fell centuries earlier than Morocco's existance.