Why were regional identities formed in the United States in the early

Why were regional identities formed in the United States in the early nineteenth century?

a. Transportation and communication were so limited that each region was isolated from news and information about other regions.
b. Most regions had aggressive devotion to radical democracy, making the other regions uneasy.
c. In order to control immigrant migration, the federal government designated certain areas for immigrants from certain countries to live.
d. As immigration increased dramatically in the early nineteenth century, immigrants tended to migrate to cities to live near people from their country of origin.
e. People wanted to defend their shared economic interests and maintain their distinct regional subcultures.

ANSWER
E