Imagine a firm's marginal abatement cost function with existing technologies is: MAC = 12 - E. If the firm adopts new pollution abatement technologies, its marginal abatement cost function will be: MAC = 6 - 0.5E. The adoption costs for the new technology are $6.If the government raises the tax on emissions from $2 to $4, the firm's total costs increase by $_____.

HINT:Total costs include tax payments, total abatement costs, and (if relevant) adoption costs for the new technology.

Select one:

a. $12.

b. $8.

c. $10.

d. $16.