The correct answer is letter A.
Lend-Lease Act corresponded to a natural development of US policy, favorable to the allied cause in the conflict then largely confined to Europe. Previously, the supply of war material to the Allies was based on the principle of cash-and-carry, ie cash payment. The exhaustion of UK dollar reserves by the end of 1940, however, made it necessary to revise this policy in light of the concept that support for the United Kingdom was vital to US national security.
