Use the Following to Answer Questions Below

Use the following to answer questions below:

-Refer to the graph of demand and marginal revenue. If a profit-maximizing monopolist with a constant unit cost equal to $20 faces the demand curve plotted in the graph, then what will the monopolist's total revenue and the profit be?

A) Total revenue: $80, profit=$40.
B) Total revenue: $160, profit=$80.
C) Total revenue: $160, profit=$120.
D) Total revenue: $240, profit=$160.