Answer:
C. The U.S. declared war on japan after it attacked Pearl Harbor
Step-by-step explanation:
The United States hadnt actually fully entered the war prior to the attacks by Japan on Pearl Harbor, they had passed several actions to lend and send money, arms and supplies to any country that needed help in their defense and whose soveraignity was important to the soveraignity and freedom of the United States, this meant sending arms and supplies to the allies, but not actively fight the war, when Japan attacked Pearl Harbor, the United States had a reason and a valud justification to declare war on Japan and by doing so, declaring war to the whole Axis power.