The berlin airlift to west berlin in 1948 and 1949 involved planes sent by
a)only the united states.
b)only great britain.
c)only canada.
d)several allied nations

The correct option is D

It was a project carried out by the United States Air Force, the Royal Air Force, the Royal Canadian Air Force, the Royal Australian Air Force, the Royal Air Force of New Zealand and the South African Air Force. The plan was risky because about four thousand tons of supplies per day seemed impossible by air, but the number of aircraft involved in the airlift grew steadily. The Americans had to be assisted by the rest of their allies, as British and French aircraft also assumed some flight missions. Per year, there were 200,000 flights, with 4,700 tm daily.

answer; people where able to travel across the u.s.a faster than any other mode of transportation,travel time was about a week,from coast to coast