a. the loss of states' rights to control their own laws
Explanation:
The main problem that the southern states had with the Union and the main reason for them to seced from the union was the fact that the Union wanted the federal government to have authority and last word over all of the States that entered the union, this basically gave power to the federal government of free will and the States should have to obbey what the federal government said, that was why they felt they were loosing control over their own laws.
