The correct answer is: C. For perfect competition.
In perfect competition, there are many firms producing an identical product, and there is freedom of entry and exit. This means that firms can easily enter or exit the market, and there are no barriers to entry. As a result, firms in a perfectly competitive market have no market power.
In a monopoly, there is only one firm producing a good or service. This means that the firm has a great deal of market power, and it can charge a higher price for its product.
In an oligopoly, there are a few firms producing a good or service. These firms are often interdependent, and they may collude to fix prices or restrict output.
In monopolistic competition, there are many firms producing similar but not identical products. This means that firms have some market power, but they are not as powerful as a monopoly.
I hope this helps! Let me know if you have any other questions.