Question 7 (1 point) Regarding Table 12.1 and related concepts, if a carbon tax of $5 per ton of carbon dioxide per year is imposed, (a) what will be the total marginal cost on Plant A, and (b) what will be the total marginal cost on Plant B? In both cases the units are dollars per ton of carbon dioxide per year. $15; $6 O$15; $12 $21; $6 $21; $12 $28; $6 $28; $12 Table 12 Cos ofreducing misiosa ens hande Emissions reduced Plant A's cost ($) Plant B's cost ($) emitted (tons) by (tons) Total Marginal Total || 0 10 9 1 1 2 2 8 3 4 6. S 3 3 6 4 4. 5 10 15 21 28 8 10 12 14 lew Cg 6 30 4 56 7 dge Universe 3 7