Accounting costs exclude implicit costs

In the figure above, when 20 units are produced the marginal cost is

A) less than $8. B) $8. C) more than $8 and less than $16. D) None of the above answers is correct.

In the above figure, the long-run average cost curve exhibits economies of scale

A) between 5 and 10 units per hour. B) between 10 and 20 units per hour. C) between 20 and 25 units per hour. D) along the entire curve.