The correct answers are A and B.
The Civil War was the culmination of four decades in which deep and entrenched economic, social and political differences were forged between the northern and southern states.
To the conditions of racial difference and slavery in which the South based its performance on its economy, which was primarily agricultural (cotton, sugar, rice and tobacco), it opposed the northern manufacturing industry, where the performance was based on the birth of a new class of proletarians, who despite not being slaves, but free citizens, had economic levels that led them to real conditions of slavery.
In turn, the Emancipation Proclamation expanded the objectives of the Civil War. While slavery had been a major problem that led to war, Lincoln's only mission at the beginning of the war was to maintain the Union. The Proclamation made slaves an explicit objective of the Union's war effort.
