If you want to make new discoveries in relation to something of the past and provide your own original analysis, what source would be the best to study, primary or secondary? Why? Explain. help pls is for now i need to send it on 5 mins max

How has the elimination of trade barriers affected the movement of goods among member countries of the european union? a. member countries are able to produce all the goods they need. b. goods can move freely among member countries. c. member countries no longer need to trade with countries outside the eu. d. larger countries are able to import more goods than smaller ones.