The main reason why the the United States did not sign the Treaty of Versailles is because they thought it was a bad idea to "punish" Germany by demanding massive reparations payments, and the US turned out to be right, since this only caused Germany to rise up militarily once again.
That would be a biography
I would say A is the Anwser.
Answer:
The Louisiana Purchase is imperative to the United States since it helped us grow over the mainland. We purchased this enormous land parcel for $15 million and multiplied the size of the US. We got the opportunity to investigate new land and work towards accomplishing Manifest Destiny, the possibility that the US ought to grow over the mainland.
