If a perfectly competitive firm is producing 500 units of output and the marginal revenue from producing the 500th unit of output is $3 and the marginal cost is $3.50, which of the following is true?

Select one:

A.The firm is producing the profit-maximizing output.

B.The firm should increase production.

C.The firm should decrease production.

D.The firm is earning a profit from producing the 500th unit.