The Figure Below Shows the Demand (D) and Supply (S)

The figure below shows the demand (D) and supply (S) curves of corn syrups.Figure 21.3

-A customs union is an organization of nations whose members:

A) have impenetrable trade barriers among themselves but impose no trade barriers on nonmembers.
B) have no trade barriers among themselves but impose common trade barriers on nonmembers.
C) have no trade barriers among themselves but each member country chooses its own trade policies with nonmember countries.
D) retaliate each other by raising reciprocal tariffs and calling for fair trade.
E) neither have trade barriers among themselves nor impose any restriction on the nonmember countries.