Which event started world war i? the sinking of the lusitania by german u-boats the assassination of archduke franz ferdinand and his wife, sophie germany’s annexation of alsace and lorraine after the franco-prussian war the russian enforcement of pan-slavism throughout slavic nations the signing of treaties in 1839 and 1867 to protect belgium’s neutrality nextreset

   The assassination of Archduke Franz Ferdinand and his wife, Sophie

Explanation:  The direct event that started the First World War is the assassination of Archduke Franz Ferdinand and his wife, Sophie. Although there were many other imperialist reasons, as well as the aspiration of ethnic groups for freedom, this event marked the direct reason for referring   ultimatum to Serbia by Austria-Hungary, the Serbian refusal of the ultimatum and declaration of war on Serbia on July 28, 1914. Subsequently, Russia and the Germans they entered the war and then many other great powers.

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where is the diagram