What event, more than any other led to wwi?

While there was much buildup pre-World War I, it is commonly understood that the assassination of Archduke Franz Ferdinand on 28 June 1914 in Sarajevo pushed the world to war as a result of a complex web of treaties and diplomatic obligations that quickly were triggered and resulted in sides being chosen.

the answer is c.

hope this : )

the correct answer is:

b) a rich merchant.