Eli Whitney's invention of the cotton gin in 1793 led to:

A. an increase in agricultural production in the South.
B. an increase in the amount of cotton the U. S. imported.
C. an increase in the number of textile mills in the South.
D. a decrease in the number of slaves in the South.

A. an increase in agricultural production in the South.

Explanation:

Eli Whitney's invention lead to the increase of the agricultural productivity in the Southern States which directly increases the use of cotton for processing of finished product (clothing and linening).

The increase in production also makes the crop to become a profitable crop which strengthen the economy of the United State of America.

new evidence is discovered.

oversights and errors are corrected,

new technology is applied to evidence.