Respuesta :
B) The Southern states developed the plantation system and rigid social classes.
Answer: B) The Southern states developed the plantation system and rigid social classes.
Explanation: Accounting for almost 60% of American exports by the Civil War, the growing of cotton in the Southern states developed the plantation system and rigid social classes. The invention of Whitney's cotton gin increased the South's dependency on cotton farming, much of which was sent to Great Britain's manufacturing centers.