Give the economic interpretation of each of the labeled areas: A, B, C, and D.

Use the following graph of the refined petroleum market to answer the questions below.

The economic interpretation of each area is as follows:
A Represents the net gain accruing to petroleum refineries (i.e., the excess of their increased profits over the external damages to recreational users), as they negotiate to increase production from 0 to output level QE.
B Represents the total amount of environmental damage associated with producing output level QE.
C Represents the loss of profit to petroleum refiners from reducing output from QC to QE.
D Represents the net gain accruing to recreational users (i.e., the excess of the reduction in damages over the profit loss incurred by producers), as they negotiate to achieve a reduction in output from QC to QE.