The significance of cotton production becoming a marketable export cro

The significance of cotton production becoming a marketable export crop for the United States in the early 1800s included all of the following EXCEPT

A) it led to the rapid development of new lands, especially the great plantations of Alabama, Mississippi, and Louisiana.
B) it led to the development and growth of the New England factory system in the mill center of Lowell, Massachusetts and then to factories and factory towns all over the New England region.
C) coastal and transatlantic shipping industries also expanded to meet the growing export demand of southern cotton to the mills of New England and the cotton mills in England.
D) it reduced the demand for slaves by cotton producers in the Deep South.

ANSWER
Answer: D