Suppose a perfectly competitive firm produces 40 units of output per-period (e.g., daily) and sells all units for the market price of $6. If average fixed cost is $2, average variable cost is $1, and marginal cost is $6, then the firm:
i. is maximizing total profit by producing and selling 40 units of output
ii. earns a per-period total profit of $120
iii. earns a per-period total profit of $240
iv. should close down in the short run and suffer a loss equal to $80.