Final answer:
The doctrine of popular sovereignty advocated for the issue of slavery to be decided by the residents at the state government level, where residents of a territory could decide whether slavery would be allowed.
Step-by-step explanation:
The doctrine of popular sovereignty advocated that the issue of slavery should be decided by the residents at the state government level (Option B), according to the principle that the people in the new territories should have the right to decide whether to allow slavery. This concept was based on the belief that citizens should be able to decide issues based on majority rule. Popular sovereignty was used to determine the status of slavery in the territories acquired from Mexico and was again applied to the Kansas-Nebraska territories in 1854, exacerbating sectional conflict. Despite its intentions, popular sovereignty led to violent struggles in regions like "Bleeding Kansas," and the principle ultimately failed to provide a peaceful solution to the question of slavery's expansion in the United States.