Number 1 is c
number two i have no idea
number 3 is c
Answer:
U.S intervened after the Japanese bombed pearl harbor.
Explanation:
The German Empire and Austria-Hungary were Allied within the Central Powers, So I assume it was the German Empire in this case, Which Declared war on Russia and France and was at war with Britain due to the Invasion of Belgium.
So the Answer is the German Empire.
Economic sanctions and military force