Which of the Following Best Summarizes the Series of Events

Which of the following best summarizes the series of events that led to the outbreak of World War II?

A) The Soviet Union attacked Poland,prompting numerous countries,including Germany and France,to declare war on the Soviet Union.
B) Germany invaded France,attempting to defeat it quickly,before Russia could fully mobilize its troops.
C) Britain invaded Germany,and Germany's ally,Austria,came to its aid.
D) Germany invaded Poland;Britain and France declared war on Germany,and Germany invaded France.
E) Austria invaded Serbia,Russia declared war on Austria,and Germany attacked France.