At a perfectly competitive firm's current

output level, average total cost is $15, average variable cost is $10, and marginal cost is $8 and increasing. If the product price is $15, what should this firm do to maximize profits?

(A) Increase the quantity of output produced.

(B) Increase the product price.

(C) Decrease the product price to increase sales.

(D) Shut down immediately.

(E) Continue to produce at its current output

level.