Hamilton Company's flexible budget cost formula for supplies, a variable cost, is $2.79 per unit of output. The company's performance report for last month showed a $5,363 favorable spending variance for supplies. During that month, 17,300 units were produced. Budgeted activity for the month had been 17,200 units. The actual cost per unit for indirect materials must have been closest to:
a. $2.17
b. $2.18
c. $2.48
d. $2.79