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.