Ideas of nationalism within its empire particularly threatened which of these European nations in 1914?

France

Britain

Germany

Austria-Hungary

The correct answer is Austria-Hungary

Nationalism started rising after numerous years of wars during the 19th century. Austria-Hungary believed that it had the right to be the great empire that it used to be and that it partially was at the moment. That's why things like world war 1 happened since countries wanted to establish themselves as great.