Many car owners and car dealers describe their different cars for sale

Many car owners and car dealers describe their different cars for sale in the local newspapers and list their asking price. Many people shopping for a used car consider the different choices listed in the paper. The absence of which condition prohibits this market from being described as perfectly competitive?

A) Buyers and sellers know the prices.
B) Firms freely enter and exit.
C) Transaction costs are low.
D) Consumers believe all firms sell identical products.

ANSWER

D