Use the Following to Answer Questions

Use the following to answer questions:
Exhibit: EPA Regulations
There are two firms: Company A and Company B. The EPA enforces regulations saying that neither firm can release more than 10 units of pollutants. Company A currently releases 10 units and Company B releases 11 units. The EPA requires B to reduce its pollution by 1 unit-the company can do this, but at a cost of $1,000. Company A, however, can reduce pollution by 1 unit for a cost of $400. Company B wants to save money by trading allowances with Company A. After negotiations, Company A agrees to sell one unit of pollutant to Company B for $650.
-(Exhibit: EPA Regulations) Refer to the exhibit. What is the total amount of pollutants released into the environment after the two firms have traded allowances?

A) 11
B) 9
C) 20
D) 10