The correct answer is B) by selling war materials to them.
The other options of the question were A) A by letting them lease warplanes and hire pilots. C) by secretly spying on Germany and Italy. D) by sending people to work in their factories.
The United States helped the allies before getting into World War II by selling war materials to them.
The United States President Franklin D. Roosevelt always tried to maintain the foreign policy of neutrality regarding European affairs. However, this did not impede some US companies and industries to sell weaponry and supplies to the European nations in conflict. The United States had to enter World War after the Japanese Air Force attacked Pearl Harbor Island in December 1941.
