A firm in a perfectly competitive industry produces its profit-maximizing quantity, 40 units. Industry price is $3, total fixed costs are $45, and total variable costs are $60. The firm's economic profit is

A) $15.
B) $30.
C) $35.
D) $60.

Profit-Maximizing Quantity

The level of production at which a business achieves the highest amount of profit, where marginal revenue equals marginal cost.

Economic Profit

Economic profit is the difference between total revenue and total costs, including both explicit and implicit costs.

Total Fixed Costs

The sum of all costs that remain constant regardless of the level of production or output in the short term.