Answer:
Option 2
Explanation:
The North gained a cause for the war as a mission to end slavery, and Europe could not intervene in a noble cause
Slaves fled plantations because they would be free in the North
The North enlisted African-American soldiers as they were now given rights, and over 180 thousand former slaves fought on the Unions side
This leaves only one option, the second one, to be selected. Also, slave owners didn't trust their slaves to fight for them loyally, especially with a deadly weapon.
