Which of the following is correct about a perfectly competitive firm? (E {:2- A. If price is lower than average variable cost, it will shut-down and incur fixed costs If price is lower than average variable cost, it will exit and incur xed costs '2: :2- C. If price is lower than average total cost, it will shut-down and incur fixed and variable costs '3: 22- D. If price is lower than average total cost, it will exit and incur xed and variable costs