The three items that apply to oligopoly are:
1. Differentiated and/or identical products
2. Firms are price setters
3. Some barriers to entering the market.
Step-by-step explanation:
Oligopoly is a market structure where a few large firms dominate the market. The following are the characteristics of an oligopoly market structure:
1. Differentiated and/or identical products: The products sold by the firms may be either differentiated or identical. Firms may produce similar products but try to differentiate them through marketing strategies or unique features.
2. Firms are price setters: Oligopoly firms have a significant market share and hence can influence the market price. Firms in oligopolies often engage in price wars, which can lead to instability in the market.
3. Some barriers to entering the market: Oligopoly markets have some barriers to entering the market, which makes it difficult for new firms to enter the market. These barriers can be in the form of economies of scale, high fixed costs, government regulations, or patents.
Therefore, the items that apply to oligopoly are differentiated and/or identical products, firms are price setters, and some barriers to entering the market.