Under perfect competition in the long run,average revenue is equal to

A) price.
B) marginal revenue.
C) average total cost.
D) marginal cost.
E) All of the choices are equal to average revenue under perfect competition.

In a perfectly competitive market, firms are price takers, meaning the price is determined by the market. Under these conditions, average revenue (AR) is equal to the price (P) because each unit of the good is sold at the market price. Marginal revenue (MR) is also equal to the price because the revenue from selling one more unit is exactly the price. In the long run, firms adjust their output so that average total cost (ATC) equals price to ensure normal profit, making ATC equal to AR. Similarly, firms produce where marginal cost (MC) equals price to maximize profit, making MC equal to AR as well. Therefore, all the choices are equal to average revenue under perfect competition in the long run.