The. private demand for coal equals 8.400 . 40*Price. The supplyr of coal equals 160*Price. Because of the external costs associated with coal burning. the social demand for coal equals 3.4oo . 4U*(Price + 10}. The social optimum {which recognizes the external costs of coal burning} could he realized by
a. imposing a $5 tax on producers and a $5 tax on consumers.
b.imposing a $113 tax per unit on producers.
c. imposing a $10 tax per unit on consumers.
d. all of the above.
