Which of the following was a cause for WWI?
O The alliance system allowed nations that were not in direct conflict with one another into a war
Increasing nationalism fueled imperialism and created tensions between nations
O European nations built up and increased their militaries in competition with each other
All of the above

Respuesta :

Answer:

The alliance system

Explanation:

German government's guarantee to offer aid to Austria-Hungary, and Russia's danger to counter if Austria-Hungary attacked Serbia made the alliance together framework and instrument for animosity. As proven by the evidence, the hostility between certain powers was uncontrollable therefore causing the outbreak of WW1.