Barriers to trade:

a. save jobs in unprotected industries at $231,289 per job per year

b. cost consumers billions of dollars per year.

c. are a political issue but affect the cost of imports only marginally.

d. none of the above.

B. Cost consumers billions of dollars per year.

Explanation:

Cost consumer billion per each year of trading stands as the main barrier to trading, and in this form, affects trading, not in one country but the whole system at large.

Trade is explained to concerned with facilitating the exchange of goods and services in the economy. Many think that trade and commerce are the same terms and can be used interchangeably. But the fact is both the terms are different from each other and carry different meanings. Trade simply means buying and selling of goods and services in return for money or money’s worth.

Scope of commerce is wider than that of trade, which not only refers to the exchange of goods and services but also includes all those activities that are vital for the completion of that exchange.

i think the answer to your question is b. directive