If an industry evolves from monopolistic competition to oligopoly, we would expect

A) the four-firm concentration ratio to decrease.
B) the four-firm concentration ratio to increase.
C) the four-firm concentration ratio to remain the same.
D) barriers to entry to weaken.

Barriers to Entry

Obstacles that make it difficult for new competitors to enter a market.

Monopolistic Competition

A market structure characterized by many sellers offering products that are similar but not identical, allowing for some degree of market power.

Four-Firm Concentration

is a metric that measures the total market share held by the four largest firms within an industry, indicating the level of market concentration and competition.