Which of the Following Describes the Role Westward Migration Played

Which of the following describes the role westward migration played in the development of the South?

A) Canals dug west of the Mississippi created short-term prosperity, but soon failed due to flooding.
B) A slave-based plantation economy was quickly established in states like Alabama and Mississippi.
C) The area west of the Mississippi, both in the South and the North, became economically isolated from the eastern United States.
D) The South developed an extensive railroad system to transport goods from west to east.
E) Southern congressmen voted to reopen the slave trade with Africa to supply new tobacco plantations west of the Mississippi.