Which statement is TRUE of firms in both perfect competition and monopolistic competition?

A) The long-run price is equal to marginal revenue,marginal cost,and average total cost.
B) Long-run economic profits are equal to zero.
C) The long-run level of output is at the point where average total cost is minimized.
D) Price is equal to marginal cost,ensuring that the efficient level of output is produced.

Perfect Competition

A market structure characterized by an infinite number of small firms, identical products, and easy market entry and exit, leading to companies not having pricing power.

Monopolistic Competition

A market structure characterized by many firms selling products that are similar but not identical, allowing for some differentiation and price control.

Long-Run Economic Profits

The sustained extra income a firm generates when all inputs are variable, indicating the firm's long-term competitive advantage.