The correct answer is “many ethnic groups wanted their own nation-states.”
Central and Eastern Europe experienced ethnic tensions in the early 1900s primarily because many ethnic groups wanted their own nation-states.
Central and Europe nations lived serious moments of ethnic tension in the early 1900s that produced many conflicts in the region. The reason: Many ethnic groups wanted their own nation-states. Their struggle for Independence and liberty caused many lives to end. For instance, there was the case of the assassination of Archduke Franz Ferdinand and his wife in Sarajevo. This caused Austria-Hungary declared war on Serbia and was the beginning of World War 1.
The other options of the question were, a) similarities in cultures and tradition caused problems, b) military powers were unable to stop the conflicts between ethnic groups, and c) many ethnic groups shared unlimited amounts of territory.
