The answer to question is A the sixth century.
Hope this helps;)
Eli Whitney is credited with putting the concept of using mass-produced interchangeable parts into practice. He came up with this concept during a war, when he used these parts to create guns.
The Berlin airlift, organized by the United States, was aimed at giving goods/resources to citizens of West Berlin. This airlift lasted roughly a year and the US provided over 2 million tons of cargo to these citizens. Without this airlift and support from the United States, West Berlin was in danger of falling under the control of the Soviet Union (who at this time already controlled East Berlin).
