OP Technologies Manufacturing manufactures small parts and uses an activity-based costing system. Est. Indirect Activity Activity Costs Allocation base Cost allocation rate Materials $79,000 Material moves $5.00/move Assembling $248,000 Machine hours $9.00/machine hour Packaging $70,000 # of finished units $1.00/finished unit The following parts were produced in October with the following information. The company incurs no direct labor costs. Part # Produced Materials Costs #Moves Machine Hrs. 2,350 $3,200 1,000 150 6,000 $8,500 2,000 4,550 $9,000 2,800 1,700 525 Total unit cost for part B is closest to (rounded to two decimal places) O A. $4.87 O B. $5.06 OC. $7.09 OD. $3.45