The battle of Gettysburg was the turning point of the war, after which the South’s fortunes declined. Option C is correct.
The Union and Confederate forces fought in the Battle of Gettysburg on July 1–3, 1863, in and around the town of Gettysburg, Pennsylvania, during the American Civil War. The human toll resulted from the battle was the largest number of the entire war and is often described as the war's turning point.