Tirri Corporation has provided the following information:

	Cost per Unit	Cost per Period
Direct materials	$ 7.00
Direct labor	$ 4.10
Variable manufacturing overhead	$ 1.50
Fixed manufacturing overhead		$ 23,400
Sales commissions	$ 1.10
Variable administrative expense	$ 0.80
Fixed selling and administrative expense		$ 7,800

If the selling price is $27.10 per unit, the contribution margin per unit sold is closest to:

a. $12.60

b. $7.40

c. $16.00

d. $10.50