(Table: Prices and Demand) Look at the Table Prices and Demand.The

(Table: Prices and Demand) Look at the table Prices and Demand.The New Orleans Saints have a monopoly on Saints logo baseball hats.The Saints sell at most one hat to each customer, and the table shows each customer's willingness to pay.The marginal cost of producing a hat is $18.If the Saints increase the number of hats they sell from 4 to 5, the price effect is a(n):
A.decrease in total revenue of $20
B.increase in total revenue of $20
C.decrease in total revenue of $8
D.increase in total revenue of $8.