What key event led to the outbreak of World War I?

(1 point)
Responses

the rise of a fascist German chancellor

the rise of a fascist German chancellor

the assassination of an Austrian archduke

the assassination of an Austrian archduke

invasion of Vienna by Serbs

invasion of Vienna by Serbs

the seizure of Romania by Bulgaria

1 answer

The key event that led to the outbreak of World War I was the assassination of an Austrian archduke.