8. Northern Star sells several products. Information of average revenue and costs is: Selling price per unit $8.00 Variable costs per unit: Direct material $3.00 Direct manufacturing labour $2.60 Manufacturing overhead $0.40 Selling costs $2.00 Annual fixed costs $96,000 The company sells 12,000 units at the end of the year. The contribution margin per unit is: a. $11.00 b. $2.00 C. $0.00 d $14.00 9. If production is within the relevant range and volume increase, what cost behaviours occur? Variable costs per unit Fixed costs per unit a. No change Increase b. No change Decrease Increase No change d. Decrease Increase