The events that were the IMMEDIATE cause of World War I:
A Archduke Franz Ferdinand is assassinated, Austria declares war on Serbia, all the allies join in.%0D%0A%0D%0AArchduke Franz Ferdinand is assassinated, Austria declares war on Serbia, all the allies join
B Czar Nicholas is assassinated, Russia declares war on France, all the allies join in
C Woodrow Wilson is assassinated, America declares war on Germany, Russia joins in
D All of the above
D All of the above
These events were all part of the complex series of events that eventually led to the outbreak of World War I. The assassination of Archduke Franz Ferdinand in 1914 by a Serbian nationalist was the immediate trigger for the war, leading Austria-Hungary to declare war on Serbia. This set off a chain reaction of alliances being activated, with Russia, Germany, France, and other countries joining in the conflict. The assassination of Czar Nicholas of Russia and the involvement of the United States under Woodrow Wilson also played significant roles in escalating the conflict.