Figure 6.5 -Figure 6.5 Shows the Short-Run and Long-Run Effects of an of an Increase

Figure 6.5
-Figure 6.5 shows the short-run and long-run effects of an increase in demand of an industry. The market is in equilibrium at point A, where 100 identical firms produce 6 units of a product per hour. If the market demand curve shifts to the right, which of the following statements is true in the short-run?

A) The market price rises to $12, which is greater than the average total cost.
B) Each existing firm maximizes its profit by producing the output where marginal cost equals $12.
C) Each existing firm produces two more units per hour, compared to its initial profit maximizing output level at point A.
D) all of the above