Which of the Following Explains the Impact of the Expansion

Which of the following explains the impact of the expansion of international trade on the demand for less skilled workers in the United States?

A) An increase in international trade has increased the demand for less skilled workers.
B) An increase in international trade has decreased the demand for less skilled workers.
C) An increase in international trade has had little impact on the demand for less skilled workers.
D) The impact of the expansion of international trade on the demand for less skilled workers in the United States varies from year to year.