Answer:
The right choice is:
The separation between East and West.
Step-by-step explanation:
The Berlin Wall was built in 1961. The German Communist authorities decided to erect the barrier to stop the exodus of East Berliners (the communist half of the city) to the Western part of the city. It was under surveillance by guards all along. It did not only become a symbol of the division of the city and of Germany, it also turned into a symbol of the division of Europe into a free a and democratic West and a Communist Eastern Bloc. Parts of the wall were toppled in the night of November 9, 1989, and those images also became a historic symbol of the fall of comunism.