Answer:
The correct answer is option C.
Step-by-step explanation:
In a perfectly market a firm faces a horizontal line demand curve at the fixed price. This horizontal line represents demand, price line, average revenue, and marginal revenue.
A firm will be able to maximize its profit by producing at the level of output where the price is equal to marginal cost. At this point, the additional cost of producing the last unit is equal to the additional revenue generated from the last unit.