The Following Data Show the Relationship Between Output,total Costs,and Total

The following data show the relationship between output,total costs,and total revenue for a pure monopoly Within which of the following output ranges does the firm earn maximum economic profits?

A) 50 to 60 units
B) 60 to 70 units
C) 70 to 80 units
D) 80 to 90 units
In output range 60-70,profit is $300.This is higher than profits in any other range.