The U. S. responded to the blockade of Berlin by: 1. air lifting supplies into Berlin for more than a year.
2. abandoning Berlin to the Soviets.
3. sending troops to fight Soviet forces in Germany.
4. ignoring Soviet attempts to convert Berlin into a Communist city.

2

In response to the Soviet blockade of land routes into West Berlin, the United States begins a massive airlift of food, water, and medicine to the citizens of the besieged city. For nearly a year, supplies from American planes sustained the over 2 million people in West Berlin

it refers to race, i am pretty sure this was a popular term in nazi germany or something.