The answer is Russia's mobilization, the assassination of archduke Ferdinand, and imperialism and expansion.
The correct answers are number 1) Russia’s mobilizations, 3) the assassination of the Archduke, and 4) imperialism and expansion.
According to the excerpt, the causes of World War 1 were Russia’s mobilizations, the assassination of the Archduke, and imperialism and expansion.
There were many reasons to start World War 1 in that conflicted European region. Of course, one of the most important was the assassination of the Archduke Franz Ferdinand, because it was the beginning of a series of events that culminated with World War 1. Austria-Hungary declared war on Serbia on July 28, 1914. What happened next was that Russia began to mobilize its troops and got ready for war.