Which statement best explains why the assassination of Archduke Franz Ferdinand contributed to the beginning of World War I?

A. It overthrew a monarchy, which triggered nationalist revolutions in several other European nations.

B. It convinced Austrian archduke Franz Ferdinand that Serbia was planning to invade, which prompted Austria-Hungary to attack
first

C. It led to war between countries that were part of the Triple Alliance and the Triple Entente, which caused the remaining alliance members to join the war against each other.

D. It demonstrated the weakness of Austria-Hungary, which encouraged France and Russia to attack disputed territory in Central Europe.