When was the Wall in Berlin opened for everyone?

EDITORIAL LEARNING AID

Why is this answer correct?

On 9 November 1989 the border guards opened the crossings after the new travel regulations had been announced. In 1987 the Wall was still standing when Ronald Reagan gave his speech at the Brandenburg Gate. By 1992 and 1995 the Wall had already been demolished.

9 November 1989: the Wall opens.

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