One. The Battle of Antietam.
The reason I say one is because the Confederacy has better War Generals, they had a more experienced militia. That’s why they were undefeated for so long. But The battle of Antietam of 1862 was the battle the Union, the North, celebrated because of their first victory against the Confederacy, the South.
A) He wanted to quickly end the war in the Pacific without invading Japan.
D seems to be the most correct. Hope that helps!
If possible I'd say all of them except the fourth one down (parts of ecosystems are independant) but if not I'd say the most valid one is the second one down (healthy ecosystems help animals)