If a Perfectly Competitive Firm Is Operating in the Short

If a perfectly competitive firm is operating in the short run and seeks to maximize profit, what action should the firm take?

A) Choose the output where per-unit profit is greatest.
B) Increase output whenever price exceeds marginal cost.
C) Increase output whenever marginal revenue is less than marginal cost.
D) Increase output whenever marginal cost is less than average total cost.