The correct answer to this question is exports. Every years trillions of goods and services are exported. Exports are the goods and services sent over to another country for sale. In the United States, the main exports are foods and beverages. The United States also trades the most with Canada and Mexico.
For ever billion exports traded by an industry, wages increase by approximately 2 percent. The Constituion is where it states that exports are unable to be taxed. Article 1, Section 9 of the Constituion states "No Tax or Duty shall be laid on Articles exported from any State".