Read the passage. Chief among these [economic developments] was the rise of a great cotton-growing industry in the South, stimulated by the introduction of new types of cotton and by Eli Whitney’s invention in 1793 of the cotton gin, which separated the seeds from cotton. At the same time, the Industrial Revolution, which made textile manufacturing a large-scale operation, vastly increased the demand for raw cotton. And the opening of new lands in the West after 1812 greatly extended the area available for cotton cultivation. Cotton culture moved rapidly from the Tidewater states on the East Coast through much of the lower South to the delta region of the Mississippi and eventually to Texas.

–"Westward Expansion and Regional Differences,” Outline of US History,
US Department of State

Which statement best describes the Southern states’ practice of slavery in the wake of the Industrial Revolution of the early 1800s?

The use of machines for agricultural automation made slavery economically obsolete, resulting in slavery’s decline.
The use of machines for automation significantly increased agricultural yields, requiring more enslaved people to process harvests and resulting in slavery’s expansion.
The influx of European immigrants seeking industrial work expanded the pool of available labor that proved less expensive, resulting in slavery’s decline.
The influx of European immigrants seeking industrial work affected election outcomes in favor of states’ rights, resulting in slavery’s expansion.