Answer:
The answer is: letter A, Its allies ran out of money with which to purchase the equipment.
Step-by-step explanation:
After France was defeated by the Nazis, Britain also struggled to fight Germany. Its prime minister, Winston Churchill, requested help from the US President, Roosevelt. The President agreed by allowing the exchange of its destroyers (which were already outdated) with leases on the British bases (particularly, 99 years). However, the war took a toll on Britain's economy. As it was asking for help again, Roosevelt stated that it won't be able to provide financial aid when it comes to the military supplies that it was supposed to ship.
After convincing the Congress, Roosevelt began to introduced the "Lend-Lease System" of war equipment. So, this happened because US' foreign allied ran out of money to purchase such equipment.
Thus, this explains the answer.