The correct answer is A) had sustained very little destruction.
In the wake of the Civil War, compared to the South the North had sustained very little destruction.
What happened was that the Northern states were more industrialized than the southern states, so the economy was better and living and education opportunities were also better than in the south. The North had more money for reconstruction.
The case of the southern states was different. They completely based their economies on slavery to produce the cash crops in the large plantations. Those crops were exported to Europe. So landowners needed extra hands and slavery was the solution. Many of the battles during the Civil Wars had been fought south the territory of Virginia, and so much destruction was left in those southern places.