Question

the berlin wall became a symbol of the cold war because it
was painted in somber colors.
literally divided the east and the west.
was made of inexpensive building materials.
failed to stop the flow of defectors.

Explanation:

The Berlin Wall physically separated communist East Berlin (aligned with the Eastern Bloc) and democratic West Berlin (aligned with the Western Bloc) during the Cold War, embodying the ideological and geopolitical division between the two opposing sides. The other options are incorrect: its color, building materials, or its partial failure to stop defectors did not make it a Cold War symbol.

Answer:

literally divided the East and the West.