2. The principal reason the market fails to incorporate the costs or benefits of externalities is because

a. externalities are consciously hidden by firms that generate them.

b. they are government generated.

c. there are no clear-cut, identifiable ownership rights to these externalities.

d. externalities are costly, and neither firms nor consumers are interested in buying or selling them.

e. externalities are typically undervalued, so that there is no market to buy or sell them at their real prices.