(A) The assassination of Archduke Ferdinand, the sinking of the USS Maine and the Zimmerman Telegram
(B) Militarism, Alliances, Imperialism and Nationalism.
(C) ** The assassination of Archduke Ferdinand, the sinking of the Lusitania and the Zimmerman Telegram
(D) Mayhem, Allegiances, Integrity and Nuance
EXPLANATIONS BELOW
Concept note-1: -The immediate cause of World War I that made the aforementioned items come into play (alliances, imperialism, militarism, nationalism) was the assassination of Archduke Franz Ferdinand of Austria-Hungary.
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 assassination of Archduke Franz Ferdinand, heir to the Austro-Hungarian throne, and his wife Sophie in Sarajevo (the capital of the Austro-Hungarian province of Bosnia-Herzegovina) on 28 June 1914 eventually led to the outbreak of the First World War.
Concept note-4: -Nationalism played a specific role in World War I when Archduke Ferdinand and his wife were assassinated by Princip, a member of a Serbian nationalist terrorist group fighting against Austria-Hungary’s rule over Bosnia.