Two Firms,A and B,each Currently Dump 50 Tons of Chemicals

Two firms,A and B,each currently dump 50 tons of chemicals into the local river.The government has decided to reduce the pollution and from now on will require a pollution permit for each ton of pollution dumped into the river.The government gives each firm 20 pollution permits,which it can either use or sell to the other firm.It costs Firm A $100 for each ton of pollution that it eliminates before it reaches the river,and it costs Firm B $50 for each ton of pollution that it eliminates before it reaches the river.After the two firms buy or sell pollution permits from each other,we would expect that Firm A will dump

A) 10 fewer tons of pollution into the river, and Firm B will dump 50 fewer tons of pollution into the river.
B) 50 fewer tons of pollution into the river, and Firm B will dump 10 fewer tons of pollution into the river.
C) 30 fewer tons of pollution into the river, and Firm B will dump 30 fewer tons of pollution into the river.
D) 10 more tons of pollution into the river, and Firm B will dump 50 fewer tons of pollution into the river.