Prior to entering the war, the United States A) Had an agreement with Germany to not get involved
B) Had plans to enter the war to defeat the Axis Powers.
C) Supplied the Allies with ships and war supplies
D) Bombed Japan.

I am 99% sure it is A. Had an agreement with Germany to not get involved

The answer is C, Supplying the Allies with ships and war supplies.

The other ones are not correct, because,

A: Though the US did have a policy of isolationism, they never had a formal agreement with Germany to not get involved.

B: The US never really had plans to enter the war to defeat the axis powers, mainly because they wanted to stay out of any future European wars. However, they were more allied leaning, and gave them supplies.

D: It was actually Japan who bombed the US in 1941 which brought them into the war. However, there were former incidents that raised tensions between the two, such as the USA Panay destruction.

Hope this helps! :)