Which of the Following Statements Accurately Describes the German Blitzkrieg

Which of the following statements accurately describes the German blitzkrieg?

A) It was another name for the months-long stalemate at the beginning of the war as Hitler's generals waited out the winter.
B) It was a relatively ineffective and slow war tactic, which led to the extended length of the Second World War.
C) It began during the invasion of the Sudetenland, which triggered French and British declarations of war.
D) It was based on espionage, with spies and agents undermining enemy governments ahead of an invasion.
E) It was centered on speed and stunned defenders who faced coordinated air and land forces in western Europe.