Many United States companies have, unfortunately, made the search for legal protection from import competition into a major line of work. Since 1980 the United States international Trade Commission (IT C) has received about 280 complaints alleging damage from imports that benefit from subsidies by foreign governments. Another 340 charge that foreign companies “dumped” their products in thee United States at “less than fair value.” Even when no unfair practices are alleged, the simple claim that an industry has been injured by imports is sufficient grounds to seek relief. 　　Contrary to the general impression, this quest for import relief has hurt more companies than it has helped. As corporations begin to function globally, they develop an intricate web of marketing, production, and research relationships. The complexity of these relationships makes it unlikely that a system of import relief laws will meet the strategic needs of all the units under the same parent company, №. Suppose a United States-owned company establishes an overseas plant to manufacture a product while its competitor makes the same product in the United States. If the competitor can prove injury from the imports-and that the United States company received a subsidy from a foreign government to build its plant abroad-the United States company’s products will be uncompetitive in the United States, since they would be subject to duties. 　　Perhaps the most brazen ease occurred when the ITC investigated allegations that Canadian companies were injuring the United States salt industry by dumping rock salt, used to de-ice roads. The bizarre aspect of the complaint was that a foreign conglomerate with United States operations was crying for help against a United States company with foreign operations. The “United States” company claiming injury was a subsidiary of a Dutch conglomerate, while the “Canadian” companies included a subsidiary of a Chicago firm that was the second-largest domestic producer of rock salt. The last paragraph performs which of the following functions in the passage?