While vertical intra-industry trade refers to trade between firms that produce ........., horizontal intra-industry trade refers to trade between firms that produce........... Question 6 Answer a. substitute goods across industries, products that differ only in price and quality or in minor characteristics. b. goods and intermediate goods that belong to competing industries, products that differ only in price and quality or in minor characteristics. c. complementary goods across industries, products that differ only in price and quality or in minor characteristics. d. goods and intermediate goods that belong to different industries, products that differ only in price and quality or in minor characteristics. e. goods and intermediate goods that belong to the same industry, products that differ only in price and quality or in minor characteristics