Which statement does not accurately describe events during the cold war?

a.
the united states and its western allies formed the north atlantic treaty organization (nato).

b.
the united states built a series of defensive fortifications in the 1950s called the iron curtain.

c.
the german nation and the city of berlin were finally reunited in 1989.

d.
the collapse of the soviet union allowed the nations of eastern europe to form democratic governments.