A) is true and is a justification for tariffs to protect domestic jobs.
B) is true and it is has been found that tariffs in these cases can save thousands of jobs and benefit the economy.
C) is true but the benefits of free trade are still such that tariffs should not be placed on these industries.
D) is not true, as evidenced by the fact that the United States carries on a lot of trade with countries that have lower wages.