The Following Figure Depicts a Firm's Long-Run Average Total Cost

The following figure depicts a firm's long-run average total cost and selected short-run average total cost curves.

-Refer to the figure above.The firm is currently producing at point D.What prevents the firm from producing at E?

A) Beyond D, the cost of labor becomes too expensive.
B) The firm can produce at E in the short run but decides not to do so, because at D the firm maximizes profits.
C) Producing at E is currently impossible, because too much time is needed to gather the level of capital to produce at E.
D) It is uncertain if producing at E is better than producing at D, because prices are likely to rise in the future.