Final answer:
The Wilmot Proviso aimed to ban slavery in all territories acquired from Mexico, which intensified the debate over slavery, marking a significant moment in the growing division between the North and South. The correct answer is option B.
Step-by-step explanation:
The Wilmot Proviso, introduced by Pennsylvania congressman David Wilmot, aimed to address the issue of slavery following the Mexican-American War. Specifically, the Proviso declared that slavery would be banned from all territories that Mexico ceded to the United States. This proposal intensified the ongoing debate over slavery and signaled increasing sectional divisions between the North and South. Though it passed in the House of Representatives, the Proviso was ultimately defeated in the Senate, and as such, it never became law. However, its introduction was pivotal in stoking the tensions that eventually led to the Civil War, as it brought the topic of slavery's expansion into the national spotlight once again.