Economists tend to focus on one structural aspect of market organization that is more important than others. It is:

a. the number of buyers and sellers.

b. product homogeneity or differentiation.

c. the quality of market information.

d. entry and exit conditions.

The answer is b. product homogeneity or differentiation

Markets can be either perfect competition or of imperfect competition. Where perfect competition refers to large number of buyers and sellers imperfect competition gives the bargaining power to the producers. But the nature of the produce plays a crucial role in the categorizing a firm and also defining its trait. Even if a market structure consists of large number of buyers and sellers but presence of product differentiation among the firms leads to each firm having monopoly power over their product. This makes the firm imperfectly competitive. But product homogeneity would have made the firms perfectly competitive.