From 1961 to 1989, Berlin was …

EDITORIAL LEARNING AID

Why is this answer correct?

From 1961 to 1989 the Wall divided East and West Berlin. Both halves of the city had their own mayors, and West Berlin could be reached by road, rail and plane. Berlin was not a separate state but a special area under Allied responsibility.

1961 to 1989: Berlin divided by the Wall.

This translation and explanation are editorial learning aids. The official German wording and answer key govern the examination.