Which of the Following Distinguishes the Short Run from the Long

Multiple Choice

Which of the following distinguishes the short run from the long run in pure competition?

A) Firms can enter and exit the market in the long run but not in the short run.
B) Firms attempt to maximize profits in the long run but not in the short run.
C) Firms use the MR = MC rule to maximize profits in the short run but not in the long run.
D) The quantity of labor hired can vary in the long run but not in the short run.