The correct answer is B. industry grew as the cotton gin improved efficiency in southern plantations. This unfortunately led to the growth of the enslaved worker population to meet demands for cotton.
The invention of the cotton gin in 1793 by Eli Whitney significantly increased the efficiency of cotton production in the South, making it a highly profitable crop. As a result, the demand for cotton surged, leading to the expansion of cotton plantations and, consequently, an increase in the enslaved workforce to meet this demand. This growth in the cotton industry also contributed to the industrial growth in the North, where textile manufacturing took off, as Northern factories relied heavily on Southern cotton as a raw material.