As a Whole, Nations Are Better Off After Trade and Specialization

As a whole, nations are better off after trade and specialization because:

A) nations experience an outward shift of their production possibilities curve.
B) nations can consume along their production possibilities curve, which is above of their consumption possibilities curve.
C) nations can consume along their consumption possibilities curve, which is above of their production possibilities curve.
D) nations can consume along their consumption possibilities curve, which is below of their production possibilities curve.