Railroads not only led to an increase in the ability to transport raw materials, but they also led to an "<span>B. increase in the demand for raw materials," since it provided for far more opportunities to use such materials all over the country. </span>
The answer is going to be c. Populism
All seem false, but D is the only one I can think of a reason it might be true. As Africa’s has decreased steadily as globalization increased.
Among the 12th and 15th centuries, the European economy was transformed by the interconnecting of river and sea trade routes, producing Europe to become one of the world's most wealthy trading networks. Before the 12th century, the main obstacle to trade east of the Strait of Gibraltar was the absence of commercial incentive rather than inadequate ship design.
Many lands previous unfamiliar to Europeans were discovered by them during this period, though most were already populated. European overseas exploration directed to the advance of global trade and the European colonial empires, with the contact between the Old World (Europe, Asia, and Africa) and the New World (the Americas and Australia).
To sum up, The wealth that could be made through trade was the major motive for the European exploration between 1400 and 1800, letter A.