Producer surplus is most accurately defined as the.（）
A. difference between the opportunity cost of producing the last unit of a good or service and the price received for that unit.
B. sum of the differences between the marginal benefit and the marginal cost for each unit of good produced and consumed over the total number of units produced and consumed.
C. sum of the differences between the price received for each unit of good produced and the opportunity cost of each unit.
参考答案：C
解析：
Producer surplus is the sum of the differences between the price received for each unit of good produced and the opportunity cost of each unit, for the total units produced. Producer surplus results when the market price for a good or service exceeds the marginal cost producing it.