The correct answer is D. Oligopoly.
In an oligopoly, there are a small number of firms that produce a large share of the market. This means that each firm’s decisions about price and output can have a significant impact on the other firms in the market. As a result, firms in an oligopoly are mutually interdependent in their pricing-output decisions.
In a perfect competition, there are a large number of firms that produce a small share of the market. This means that no one firm has a significant impact on the market, and firms can freely choose their prices and outputs without worrying about the reactions of other firms.
In a monopolistic competition, there are a large number of firms that produce differentiated products. This means that each firm has some control over its price, but it also faces competition from other firms that produce similar products.
In a monopsony, there is only one buyer in the market. This means that the buyer has a lot of power and can dictate prices to the sellers.
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