What caused south carolina to secede from the united states?

a. debate over the expansion of slavery into the territories

b. the breakdown of the party system
c. increased sectional tensions due to new laws
d. the growth of the anti-slavery movement

The correct answer among all the other choices is A. Debate over the expansion of slavery into the territories. This caused South Carolina to secede from the United States. Thank you for posting your question. I hope this answer helped you. Let me know if you need more help. 

Bis correct according to edgnuity , thaaanks