Answer:
The correct answer is A. The secession of South Carolina from the Union in 1860 was prompted by the election of Abraham Lincoln as President.
Step-by-step explanation:
In 1860, the abolitionist Republican Abraham Lincoln won in the presidential elections of that year. South Carolina, fearing that Lincoln would definitively abolish slavery in the country, decided to separate from the United States on December 20 of that year, being the first American state to separate itself from the rest of the country. Subsequently, ten other states would also be separated from the United States, and immediately join to form the Confederate States of America.