10. Northern Star sells several products. Information of average revenue and costs is: Selling price per unit $9.00 Variable costs perunit: 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 unitis: a. $1.00 b. $2.00 C.$3.00 d.$4.00