Question

Which condition best explains why World War I started?

O a system of military alliances in Europe and nationalism on the Balkan Peninsula
O the clash of capitalism and communism in European nations
O imperialism in South America and Asia and the rapid buildup of armies and navies
O the spread of communism from Russia into western Asia

Answer 1

a system of military alliances in Europe and nationalism on the Balkan Peninsula

Explanation: hope this helps!