Answer: 3. Lend-Lease Act
Step-by-step explanation:
FDR had campaigned under a slogan saying that he would keep the United States out of the war and so the United States was neutral during the first years of the second World War even though they were still strongly pro-British.
In order to preserve that neutrality whilst still supporting the British and other allies, Congress signed the Lend-Lease act which allowed the U.S. to lend or lease supplies to Britain and her allies throughout the war. This was vital in stopping the German advance and winning the war.