Which of the following is a characteristic of a perfectly-competitive market?
a. It is difficult for new firms to enter the market due to barriers to entry.
b. The output sold by a particular firm may be quite different from the output sold by other firms in the market.
c. All firms produce and sell a standardized or undifferentiated product.
d. The firms are price setters.
c. All firms produce and sell a standardized orundifferentiated product