Answer:
B) Archduke Ferdinand is shot, A) Russia declares war on Austria, C) America enters the war
Step-by-step explanation:
These three events are all major events that lead to the beginning and end of World War II. The assassination of Archduke Ferdinand is what is considered to be the event that led to WWII. Ferdinand and his wife had a bomb thrown at their motorcade and after it misses, they are shortly thereafter on the same day they are shot and killed June 28, 1914. So this was the first event in this series.
Very shortly thereafter Austria was actually the one to declare war on Russia. After Austria declared war on Serbia (the ones who assassinated Ferdinand) Russia tried to bring a diplomatic resolution to the problem in the months to follow. However, after constant aggression from Austria, Russia began mobilizing it's military for war. Austria finally declares war on Russia on August 6th, 1914
Almost three decades later, after constant threat of attack from Germany and the Axis powers, Japan leads an attack on U.S. soil. We know this attack was the attack on Pearl Harbor which occurred December 7th, 1941. That very next day (December 8th, 1941) the United States joins World War II.