What was the "spark" that set off world war i? germany’s invasion of neutral belgium the assassination of archduke franz ferdinand of austria by a serbian nationalist the sinking of the lusitania by a german u-boat germany's declaration of war on russia and france?

The ""spark" that definitely launched the First World War was the assassination of Austrian Archduke Franz Ferdinand in Sarajevo on June 28, 1914. The assassination was carried out on two occasions on the same day, of which the first was unsuccessful carried out by another Serbian nationalist. Later on during the return of Archduke Ferdinand and his wife Sophie, in another attempt by the Serbian nationalist Gavrio Princip,  Archduke and his wife were killed.

The answer is: B.

B.) the assassination of Archduke Franz Ferdinand of Austria by a Serbian nationalist

Explanation:

the influence of charles louis de secondant , baton montesquieu.

presidency should be the title