Concept:A free trade zone is an arrangement where member countries trade freely among themselves but keep independent policies toward non-member countries.Explanation:Member countries remove tariffs and quotas on goods traded within the zone.Each member has the right to set its own trade policies for non-members.A common external tariff is the feature of a customs union, not a free trade zone.Free movement of labor and capital belongs to a common market, not a free trade zone.Answer:The correct answer is B: different trade policies of non-member countries.