Which of the Following Led to the Great War

Which of the following led to the Great War?

A) the refusal of German leaders to become militaristic and honor their alliances when conflict in western Europe first erupted
B) the sudden dissolution of the Austro-Hungarian Empire and the rise of a Serbian Empire that soon took its place
C) Germany's continued reliance on the United States and Britain for all steel production and related products
D) Wilson's eagerness to enter the war immediately to take advantage of the many nations who had decided to give up their colonial empires
E) rivalries in Europe driven by hypernationalism, racist beliefs, imperial competition over foreign colonies, and a desire for military supremacy