Suppose that the pen-making industry is perfectly competitive. Also suppose that each current firm and any potential firms that might enter the industry all have identical cost curves, with minimum ATC = $1.25 per pen. If the market equilibrium price of pens is currently $1.50, what would you expect it to be in the long run? 

a. $0.25. 

b. $1.00.

c. $1.25. 

d. $1.50.