Srry i would totes answer but i cant :P I hope u get it right! :D
Answer:
D. The United States expanded the Monroe Doctrine Forcefully
Explanation:
Immediate Cause: Assassination of Archduke Franz Ferdinand
The immediate cause of World War I that made the aforementioned items come into play (alliances, imperialism, militarism, and nationalism) was the assassination of Archduke Franz Ferdinand of Austria-Hungary