In tropical Africa, the French were for a time the most enthusiastic railroad builders. In 1879,
soon after beginning their penetration of the Western Sudan, they laid plans for a railroad
from Senegal inland. Their first line was inaugurated in 1885 between Saint-Louis and Dakar, a distance of 163 miles. Another line, from Kayes on the Senegal River to Koulikoro on the upper Niger, was begun in 1881 and completed in 1906; this was primarily a military line whose purpose was to transport troops through unconquered territory. Yet another line, linking Konakryin French Guinea to the upper Niger, was built between 1899 and 1914, mostly for the export of natural rubber.
- Daniel R. Headrick, The Tools of Empire: Technology and European Imperialism in the Nineteenth Century
Which pair of reasons motivated the railroad construction described in the excerpt?
A. For international prestige and to import African manufactured goods
B. to influence African politics and provide work for French emigrants
C. to spread Christianity and raise local standards of living
D. for military purposes and to obtain natural resources