The answer to your question is quite simple:
Places and regions.
The answer is C. Oh, and I found a resource to back it up:
Freed of any Soviet threat, Germany invaded Poland on September 1 and ignited World War II. The Nazi-Soviet pact and Germany's three-week blitzkrieg against Poland panicked Romania, which granted refuge to members of Poland's fleeing government.
I hope this helped. Bye
Some common aspects of the war effort during the WW1 were:
rationing -since many people were working in the war effort, less people could focus on farming, so there were many shortages.
war bonds - those were used to finance the war effort
women taking over many of men's jobs, such as in factories - this later led to female suffrage!
In last summer of 1914 the ancient Austria,Russia and Germany plunged their countries into a world war which engulfed Europe in one of the bloodiest conflicts in history
