All of the Following Were Considered Causes of World War

Multiple Choice

All of the following were considered causes of World War I EXCEPT

A) A testing ground for a new mechanized war machine.
B) Assassination of the heir to the Austro-Hungarian throne.
C) Extreme nationalist sentiment throughout Europe.
D) A frenzy of international imperialism in the 19th century.
E) Europe suffered from too many years of peace.