Which set of events related to World War I is in the correct chronological order?
1)Archduke of Austria-Hungary assassinated →United States declares war on Germany →Lusitania sunk→ World War I begins
2)Lusitania sunk→ World War I begins →United States declares war on Germany →Archduke of Austria-Hungary assassinated
3)United States declares war on Germany →Archduke of Austria-Hungary assassinated →Lusitania sunk→ World War I begins
4)Archduke of Austria-Hungary assassinated →World War I begins → Lusitania sunk→United States declares war on Germany