Assume That Research Shows That American Agriculture Is the Most

Assume that research shows that American agriculture is the most efficient in the world; then:

A) if America is also efficient in the production of all other goods, there would be no gains from trade.
B) with only this information, we cannot say whether it would pay America to be a food exporter or a food importer.
C) it could never pay America to import food.
D) it would always pay America to import food.
E) none of the above is necessarily true all of the time.