(A) ** Assassination of Archduke Ferdinand
(B) Germany declares war on Bulgaria
(C) Great Britain conquered Ottoman territory
(D) German Kaiser Wilhelm was exiled to Siberia
EXPLANATIONS BELOW
Concept note-1: -Russia was generally supportive of these plots. The successful plot to assassinate Franz Ferdinand on 28 June 1914 was part of a bigger plan. The plotters hoped that by killing Franz Ferdinand, they would provoke the Austro-Hungarian Empire to declare war on Serbia.
Concept note-2: -The assassination set off a rapid chain of events, as Austria-Hungary immediately blamed the Serbian government for the attack. As large and powerful Russia supported Serbia, Austria asked for assurances that Germany would step in on its side against Russia and its allies, including France and possibly Great Britain.
Concept note-3: -The spark that set off World War I came on June 28, 1914, when a young Serbian patriot shot and killed Archduke Franz Ferdinand, the heir to the Austro-Hungarian Empire (Austria), in the city of Sarajevo.
Concept note-4: -Leading up to the Assassination Serbia was an ally with the powerful Russian Empire and Austria-Hungary was allied with Germany. When Archduke Ferdinand announced his trip to Sarajevo, Bosnian nationalists (people who wanted Bosnia to be its own country) saw their opportunity to strike at the Austrian Empire.