What event caused four additional southern states to secede from the union?

The answer is Lincoln raised an army. With the vote in 1860 of Abraham Lincoln, who competed on a message of covering slavery to where it now existed, and the achievement of the Republican Party to which he went – the first completely regional party in US history – in that voting, South Carolina separated on December 20, 1860, the first state to ever formally separate from the United States. Four months later, Georgia, Florida, Alabama, Mississippi, Texas and Louisiana separated as well.

b - those executed came from every social and economic class

is it multiple choice