The Member Countries of a Customs Union Not Only Agree

The member countries of a customs union not only agree to allow the free trade of goods between their economies, but they also agree to:

A) permit labor to migrate freely between the member countries.
B) harmonize all economic policies.
C) set common tariffs and other trade restrictions against nonmember countries.
D) let each member country set its own tariffs and other trade restrictions against outside countries.