Which of the following made it easy for the United States to supply its efforts in world war 1?

First, I need more details. But I can still give you the answer. The United States got involved in World War 1 because of a Zimmerman telegram sent to Mexico detailing German plans against the U. S in which Mexico was conquered by the U. S loosing Arizona, New Mexico, and Texas. The note was sent on April 2 1917 and 4 days later the U. S declared war against Germany.

What are the choices?