All of the following statements are true about marginal costexcept

I. marginal cost increases as production expands.

II. when marginal cost is below average cost, average cost is falling.

III. when marginal cost is above average cost, average cost is constant.

IV. when marginal cost meets the average total cost, the average total cost is at its minimum point.

II and III

I only

II only

III only

III and IV

IV only