To What Does the Term Safe Areas Refer

To what does the term safe areas refer?

A) Territory astride the recently demolished Berlin Wall claimed as neutral ground by citizens in both the Eastern and Western zones of the city.
B) The free fire zones in Kosovo which civilians were advised to avoid as only those armed combatants would be safe.
C) Demilitarized zones along the border between Croatia and Serbia.
D) Areas in Bosnia designated by the United Nations as free of violence for ethnic refugees during the civil war there.
E) Areas in Western European states bordering communist states that served as reception points for refugees in 1989.