The answer should be C- Rare Minerals. They needed these minerals to continue the war effort, and often purchased from Mexico Rare and Raw Minerals.
I hope this helps! :)
The reason for the change from isolationism to imperialism was because America was slowly becoming a superpower in the world during the 19th century. This was also due to the fact that America felt that it could maintain "peace" in the world through its power. To hold its status as a superpower, America had to take steps to establish itself around the world. The Imperial rule allowed it to compete with European states in terms of resources and money.
Map Zedong hope this helps
