ABC Inc. incurred the following costs for the last 3 months: Production in units: 40,000 50,000 60,000 Factory Rent: $10,000 $10,000 $10,000 Total Indirect Manufacturing costs: $90,000 $110,000 $130,000 Selling costs: $60,000 $75,000 $90,000 Commissions: $120,000 $150,000 $180,000 Which of the following best represents the cost equation for ABC's indirect manufacturing costs?

Multiple Choice Y = $10,000 + $2X Y = $10,000 + $1X. Y = $10,000 + $1.50X Y = $10,000 + $3X