What is meant by the concept of "trade diversion"?
◦ the replacement of a low-cost foreign supplier with a high-cost one based on membership in a trade agreement
◦ trade that is shifted between members of a customs union
◦ the creation of a free-trade area
◦ something that is predicted by theory, but has never been observed in practice
◦ an increase in economic efficiency that comes with a newly established trading relationship