Suppose Roger and Regina receive great satisfaction from their consumption of cheesecake. Regina wou purchase only one slice and would pay up to $8 for it. Roger would be willing to pay $11 for his first slice, $9 for second slice, and $5 for his third slice. The current market price is $5 per slice. Assume that the government places a $4 tax on each slice of cheesecake equilibrium price is $9. How much tax revenue will be generated from sales to Regina and Roger?

a. Zero

b. $8

c. $4

d. $12