The long-run average cost of production is defined as:

Select one:

a. total cost divided by the quantity of output the firm chooses when at least one factor is fixed.

b. total cost divided by the quantity of output the firm chooses when it can choose a production facility of any size.

c. the quantity produced by a firm that can choose any size production facility.

d. the quantity produced by a firm when at least one factor is fixed.