Two Firms, Kegareta Inc

Multiple Choice

Two firms, Kegareta Inc. and Sucio Enterprises, have access to five production processes, each one of which has a different cost and gives off a different amount of pollution. The daily costs of the processes and the corresponding number of tons of smoke emitted are shown in the accompanying table.  
Suppose the government wants to reduce pollution by 50 percent by imposing a tax of $T per day on each ton of smoke emitted. Of the options listed, what's the smallest tax, $T, that will achieve this goal?

A) $51
B) $56
C) $61
D) $54