What Is One Reason Why Would Corn Production, Which Takes

What is one reason why would corn production, which takes place in a perfectly competitive market, achieve an efficient use of resources?

A) Because a perfectly competitive firm produces at the lowest possible long run average total cost
B) Because a perfectly competitive firm produces where marginal revenue exceeds marginal cost
C) Because a perfectly competitive firm is a price maker
D) Because the goal of a perfectly competitive firm is to profit maximize