Staley Co. manufactures computer monitors. The following is a summary of its basic cost and revenue data: Per Unit Percent Sales price $ 480 100 Variable costs 312 65 Unit contribution margin $ 168 35 Assume that Staley Co. is currently selling 600 computer monitors per month and monthly fixed costs are $80,000 If an $18,000 increase in the advertising budget would increase monthly sales by $60,000, the new level of operating income for Staley Co. would be: $19,800 $20,800 $21,800 $23,800. $24,800