Answer:
B. The South had a more extensive network of railroads (more mileage of railroad tracks).
Step-by-step explanation:
The Southern railroad network was a lot poorer than the northern railroad network.
The South only had a few railroads , especially in the middle of the states of Alabama, Georgia, and the Carolinas. Florida, for example, essentially had no railroads.
The North had a much more developed network, particularly in the Great Lakes states, and the Mid-Atlantic region. This network would facilitate the industrial development of these areas that would come after the Civil War.