When externalities are present, market prices do not reflect all the social costs or benefits of the activity

In which of the following countries does health insurance not pay for most preventive care procedures?

A) Canada B) Japan C) the United Kingdom D) the United States

A linear total cost function implies that:

a. marginal costs are constant as output increases b. average total costs are continually decreasing as output increases c. a and b d. none of the above