It's better if you help US out by putting what choices you have to choose from. (A,B,C,D)
Answer:
The immediate cause of World War I that made the aforementioned items come into play (alliances, imperialism, militarism, nationalism) was the assassination of Archduke Franz Ferdinand of Austria-Hungary. In June 1914, a Serbian-nationalist terrorist group called the Black Hand sent groups to assassinate the Archduke.
It is important because if you dont compromise it could lead to bad things.