Differences in regional economic development during the 19th century produced which of these conditions in the United States at the time of the Civil War?
A The North was the nation's main industrial area.
B The South was the main destination for immigrants.
C The North was the nation's main cotton-producing area.
D The South was the nation's main transportation center for agricultural goods.
I know HistoryGuy has already answered this but he isnt the most reliable source so I just want to ask this just in case.