The second alternative is correct (B).
The Berlin Wall was a physical barrier separating Germany from two nations: West Germany and East Germany.
After the end of World War II, a dispute arose between two economic systems, capitalism and socialism, represented respectively by the United States and the USSR, which disputed world hegemony. This period became known as the Cold War.
The Berlin Wall divided Germany between one country as Soviet influence, East Germany, and the other about American capitalist influence, West Germany.
The fall of the Berlin Wall in 1989 represented the end of the Cold War and the assumption of capitalism as a hegemonic regime.