The following monthly budgeted data are available for the Stark Company: Product A $500,000 Product B $300,000 Product $900,000 Sales Variable expenses 300,000 210,000 720,000 Contribution margin $200,000 $90,000 $180,000 Budgeted operating income for the month is $220,000. Required: a) Calculate the break-even sales for the month. b) Calculate the margin of safety. c) Calculate the degree of operating leverage