How did America and Britain solve the problem of the Berlin blockade?

by transporting essential supplies to West Berlin using cargo planes
by using North Atlantic Treaty Organization troops to break the blockade
by having the United Nations declare economic sanctions on the Soviet Union
by an agreement at Potsdam that allowed the Soviets to take reparations from all of Germany

Question

How did America and Britain solve the problem of the Berlin blockade?
 	
	by transporting essential supplies to West Berlin using cargo planes
	by using North Atlantic Treaty Organization troops to break the blockade
	by having the United Nations declare economic sanctions on the Soviet Union
	by an agreement at Potsdam that allowed the Soviets to take reparations from all of Germany