Which of the following is a characteristic of an oligopoly market?

a. Each firm in an oligopoly market can take independent pricing and output decisions.

b. Barriers to entry does not exist in an oligopoly market.

c. In an oligopoly market, each firm's pricing and output decisions depend on those of its rivals.

d. There are many firms in an oligopoly market hence a firm cannot influence the market price.

e. Firms in an oligopoly market always manufacture differentiated products.