Panamint Systems Corporation is estimating activity costs associated with producing disk drives, tapes drives, and wire drives. The indirect labor can be traced to five separate activity pools. The budgeted activity cost and activity base data by product are provided below.

Activity Cost Activity Base

Procurement $370,000 Number of purchase orders

Scheduling 250,000 Number of production orders

Materials handling 500,000 Number of moves

Product development 730,000 Number of engineering changes

Production 1,500,000 Machine hours

Number of Purchase Orders	Number of Production Orders	Number of Moves	Number of Engineering Changes	Machine Hours	Number of Units
Disk drives	4,000	300	1,400	10	2,000	2,000
Tape drives	4,000	150	800	10	8,000	4,000
Wire drives	12,000	800	4,000	25	10,000	2,500

The activity-based cost for each disk drive unit is

a. $130.69

b. $394.12

c. $92.25

d. $279.57