Fourcountriesoperatewithinacustomsunion.Onecountryproposesmovingtoacommonmarketstructure.Whatadditionallevelofeconomicintegrationbetweenthecountrieswouldmostlikelyariseifthischangetookplace?Theywould: A: establishcommontradebarriersagainstnon-members. B: begintoallowfreemovementofthefactorsofproduction. C: establishcommoneconomicinstitutionsandcoordinationofeconomicpolicies.