"We must be the great arsenal of democracy - President Franklin D. Roosevelt. Which action by the United States during World War II best supports this statement?
a) The implementation of the Lend-Lease Act to provide military aid to Allied nations.
b) The formation of the United Nations to promote international cooperation and peace.
c) The establishment of the Manhattan Project to develop atomic weapons.
d) The initiation of the Marshall Plan to aid in the economic recovery of Western Europe after the war.
