How Did Westward Movement Affect the South

How did westward movement affect the South?

A) The lack of canals slowed down the use of slaves.
B) The plantation slave-based economy was replicated in Alabama and Mississippi.
C) Trade with the eastern United States was no longer seen as a priority.
D) The South developed a highly effective and large railroad system to transport goods from west to east.
E) Slavery did not expand west of the Appalachian Mountains.