What inspired john c. calhoun's theory of nullification?
a) a threat by president jackson to end the institution of slavery
b) the election of john quincy adams
c) john brown's raid on harper's ferry
d) the passing of the tariff of 1828

D) the passing of the Tariff of 1828

Explanation:

"Calhoun openly argued for a state's right to secede from the Union, as a last resort to protect its liberty and sovereignty. In his later years, Madison rebuked supporters of nullification, stating that no state had the right to nullify federal law. "

Source: https://en.wikipedia.org/wiki/John_C._Calhoun

I hope this is helpful!

they had many gains 1 one freedom for slaves the major cause of the civil war is that the   north wanted freedom for slaves but the south didn; t creaitng the civil war

another gain they have is poltiical influence

poltiical influence is a big thing everywhere even now peoplle are always trying to get the head up in poltics thats what they did by giving the republicians a good name for freeing slaves