Answer:
The correct answer is Imperialism.
Explanation:
At the end of 19th and beginning of 20th Century in Europe we had two military and political alliances - Entente and Central Powers. They competed over many issues, and one of them was the question of colonies. Members of Central Powers, mostly Germany wanted to spread its colonial territories and strengthen their imperialistic aspirations. As Entente didn't wanted to allow them to spread their influence, war was inevitable.
