Department A had 4,100 units in Work in Process that were 70% completed at the beginning of the period at a cost of $6,500. During the period, 34,400 units of direct materials were added at a cost of $75,680, and 35,500 units were completed. At the end of the period, 3,000 units were 36% completed. All materials are added at the beginning of the process. Direct labor was $28,000 and factory overhead was $4,500. The cost of the 3,000 units in process at the end of the period if the first-in, first- out method is used to cost inventories was a. $7,121 Ob. $7,641 Oc. $6,600 d. $8,682