Answer:
The correct answer is A) Confederate forces invaded Kentucky
Step-by-step explanation:
Since the beginning of the American Civil War, the commonwealth of Kentucky wanted to remain neutral in the conflict. For some time it stayed out of the conflict saving it the death and destruction that came with the war.
However, things changed when General Leonidas Polk from the Confederate army unsuccessfully tried to invade Kentucky. Once the attack was repelled, the governor of Kentucky asked the Union army for help.
This was welcomed by President Lincoln as he believed Kentucky to be very important if the Union was to be maintained.