Which one of the following, if true, would best serve as supporting evidence for the author's explanation of the economic condition of integrated steel producers? A. Those nations that derive a larger percentage of their annual steel production from minimills than the United States does also have a smaller per capita trade deficit. B. Many integrated steel producers are as adept as the specialty-steel mills at producing high-quality products to meet customer specifications. C. Integrated steel producers in the United States are rapidly adopting the production methods of Japanese integrated producers. D. Integrated steel producers in the United States are now attempting to develop a worldwide market by advertising heavily. E. Those nations in which iron-smelting operations are carried out independently of steel production must heavily subsidize those operations in order to make them profitable.