Given the following data, calculate product cost per unit under variable costing.

Direct labor $8 per unit
Direct materials $3 per unit
Overhead
Total variable overhead $30,000
Total fixed overhead $85,000
Expected units to be produced 50,000 units

a. $7 per unit
b. $13.30 per unit
c. $11.00 per unit
d. $11.60 per unit
e. $16.50 per unit