Answer :
I would go for A because the Union had 200,000 more soldiers than the confederacy.
The south produced and exported cotton and the industry was huge. The north didn't export anything because their economy was based on manufacturing. When it comes to weapons and officers, they were about the same in quality. The generals were also just as good and the familiarity with the territory being an advantage to the Union is very debatable.
What is not debatable though, is the fact that the union did have way more soldiers, making the only correct answer:
A. A larger army, but fewer exports