The market for peanut butter in Nutville is monopolistically competitive and in long-run equilibrium.

One day, consumer advocate Skippy Jif discovers that all brands of peanut butter in Nutville are identical.

Thereafter, the market becomes perfectly competitive and again reaches its long-run equilibrium. Using an appropriate diagram, explain whether each of the following variables increases, decreases, or stays the same for a typical firm in the market.

a. price

b. quantity

c. average total cost

d. marginal cost

e. profit