Final answer:
The technological development that led southern states to consider the trade-offs between economic growth and the expansion of slavery was the invention of the cotton gin.
Step-by-step explanation:
The technological development that forced inhabitants of the southern states to weigh the benefits of economic development and growth versus the costs of the expansion of slavery was A) The invention of the cotton gin. This invention by Eli Whitney in 1794 made the processing of cotton fibers much more efficient, leading to an increase in cotton production. As a result, the demand for slave labor in the South grew, as plantations expanded to meet the high cotton demands. This technological advancement thus played a critical role in entrenching the institution of slavery in the southern economy, directly impacting the social and economic fabric of the United States.
Before the Civil War, major industries were largely based in the northern states, while the southern states relied on agricultural production, with cotton and tobacco being the primary crops. It was the invention of the cotton gin that transformed the South into a region with booming economic growth built on the backs of enslaved African Americans. As cotton became the nation's primary crop, the reliance on slavery intensified. In this way, economic development and the brutal cost of expanding slavery were intertwined, reaching a precipice that would later contribute to the outbreak of the Civil War.