Which factor contributed most to the beginning of world war 1?

there are more than one but if the question is multiple choice you can choose from nationalism, imperialism,militarism, alliances, and assassinations if its a short answer than just say any one of those because they all had a big role on starting WW1

The industrial revolution led to the occurrence of modern globalization. Escalated production of household items in the industries, and an increase in the demand for such items due to increasing population, led to this revolution. This was followed by transport revolution, in which railroads were developed, and the development of international transportations also occurred.