A cell phone manufacturer has been in business for over 25 years and currently shares its market space with four other competitors. Each of the players in this market has about 20% of the market share and prices its products similarly. Over the past 10 years, the market has consolidated from 10 competitors to the current four. In which one of the following market types is the cell phone manufacturer operating? A. Perfect competition B. Monopoly C. Oligopoly D. Monopolistic competition