1. This chapter discusses many types of costs: opportunity cost, total cost, fixed cost, variable cost, average total cost and marginal cost. Fill in the type of cost that best completes each phrase below.

a. The true cost of taking some action is its _________.

b. _________ is falling when marginal cost is below it, and rising when marginal cost is above it.

c. A cost that does not depend on the quantity produced is a _________.

d. In the breakfast cereal industry in the short run, _________ includes the cost of cereals such as wheat and corn and sugar, but not the cost of the factory.

e. Profits equal total revenue minus _________.

f. The cost of producing an extra unit of output is the _________.