It's C
The north had the money, the people, and the industrial power to branch out the railroad networks. So following markets and money. The north built networks to the west.
The south in contrast was did not have the capacity to construct as much railroads as the north did so therefore there was less western expansion. As well the south had more interests building canals and shipping product of the states to England.
I believe its because they would rather die than be captured by the allies so they began killing themselves.
I think it’s d but I’m not sure