A trade agreement that removes all import tariffs between member countries, sets up common external tariffs against non-members, but does not advance toward economic integration is called:

A trade agreement that removes all import tariffs between member countries, sets up common external tariffs against non-members, but does not advance toward economic integration is called:
A . an economic union.
B . a customs union.
C . a free trade area.
D . a common market.

Answer: B