Because nobody cared until then... (the more you delete this the more ill post it moderators...)
Answer is B island hopping.
I'd say D because it has do more with the October Revolution and Commies
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.
