Both the South and the West saw an increase in population growth between 1865 and 1900.
You included no options but a major change that occurred in both the Southern and Western parts of the nation from 1865 to 1900 was that the population increased significantly.
The reasons for this were:
Northern Americans came to the South to profit from the Federal government's drive to help the South recover from the civil war.
Railroads opened up more areas in the west which allowed for people to move and settle there.
African Americans fleeing the racism in the South moved West to be safe.
In conclusion, the population changes of both the South and the West were a sign of transformation.
