The cotton gin new farmlands in the west and the demand for cotton in the Northern and European textile factories led to what?

You have not listed any options bu the closest answer is to an increase in demand for slaves in the years leading up to the civil war!

Explanation:

As a result of this, the entire Southern economy slowly started to depend on plantation and slavery. The agriculture driven by slaves finally became the largest factor in the economy.

It is why South resisted when the anti-slavery bill was brought up by Abraham Lincoln.