Carver Corporation produces a product which sells for $40. Variable manufacturing costs are $18 per unit. Fixed manufacturing costs are $5 per unit based on the current level of activity, and fixed selling and administrative costs are $4 per unit. A selling commission of 15% of the selling price is paid on each unit sold. The contribution margin per unit is: Select one: O a. $16 O b. $22 O c. $7 O d. $17