Ocean Spray Is Considered to Be an Oligopoly Firm Because

Ocean Spray is considered to be an oligopoly firm because, until the 1990s, it faced little competition in the market for fresh and frozen cranberries.Why?

A) Ocean Spray had a patent on the production of cranberries that gave the company the exclusive right to market its product for 20 years. The 20-year period ended in the 1990s.
B) Until the 1990s, Ocean Spray controlled almost the entire supply of cranberries.
C) Ocean Spray was able to achieve significant economies of scale in the production of cranberries. Beginning in the 1990s, other firms finally achieved economies of scale as well, but Ocean Spray still controls about 80 percent of the cranberry market.
D) The federal government imposed a high tariff on cranberry imports. During the 1990s the tariff was eliminated, but Ocean Spray still controls about 80 percent of the cranberry market.