If a competitive firm is selling 900 units of its product at a price of $10 per unit and earning a positive profit, then

A) its total cost is more than $9,000.
B) its marginal revenue is less than $10.
C) its average total cost is less than $10.
D) the firm cannot be a competitive firm because competitive firms cannot earn positive profits.

Competitive Firm

A company that operates in a market with many buyers and sellers, where each has a negligible effect on the market price.

Average Total Cost

The cost per unit of output, calculated by dividing the total production cost by the quantity of output produced.

Marginal Revenue

The supplementary earnings acquired from selling an extra unit of a product or service.