Answer:
a) that South Carolina is an independent state, which is therefore free to secede from the Union if it so chooses
Step-by-step explanation:
In 1860, an official secession convention met in South Carolina and issued an ordinance of secession announcing the state's withdrawal from the union. This declaration asserted the right of South Carolina to secede as the United states ad failed to uphold it's obligation therefore this revoked the agreement the State of South Carolina had with the United States.