Use the Following to Answer Question

Multiple Choice

Use the following to answer question:
-(Table: Variable Costs for Lawns) Use Table: Variable Costs for Lawns.During the summer,Alex runs a lawn-mowing service,and lawn-mowing is a perfectly competitive industry.Assume that costs are constant in each interval;so,for example,the marginal cost of mowing each of the lawns from 1 through 10 is $10.Also assume that he can only mow the quantities of lawn given in the table (and not numbers in between) .His only fixed cost is $1,000 for the mower.His variable costs include fuel,his time,and mower parts.If the price for mowing a lawn is $70,how many lawns will Alex mow?

A) 20
B) 30
C) 40
D) 50