C) Citizens who helped a runaway slave could be imprisoned
By the time the new Fugitive Slave Act passed in 1850 was enacted in the U.S., several Northern states had already abolished slavery but it was still legal in the Southern states, so many "slaves" would attempt to run away to the free states.
The Fugitive Slave Act of 1850 allowed for the capture and return of runaway slaves within the territory of the United States. It guaranteed harsh punishments, like imprisonment, for anyone helping a runaway or anyone interfering in slave's capture, guaranteed the right of slave owners and their “agents” to search for escaped slaves within the borders of free states and it compelled citizens to assist in their capture as well. It also denied slaves the right to a jury trial, among others.