What event threatened the purpose of this document and led to a new compromise?

A.
The admission of Kansas and Nebraska as either slave or free states based on popular sovereignty threatened the geographic line between slave and free states. It set a new standard for statehood.

B.
The passage of the Fugitive Slave Act threatened the sectional nature of slavery by requiring Northerners to capture and return escaped slaves. This made them complicit in slavery.

C.
The admission of California threatened the balance because it was such a large new state and fell outside the bounds of the Louisiana Territory. More free states were sure to follow.

D.
The escape of numerous enslaved persons along the Underground Railroad threatened the limits placed on abolitionists. It made clear that abolitionist forces had no intention of abiding by federal law.