Department A had 4,900 units in Work in Process that were 79% completed at the beginning of the period at a cost of $6,400. During the period, 35,600 units of direct materials were added at a cost of $85,440, and 37,800 units were completed. At the end of the period, 2,700 units were 25% completed. All materials are added at the beginning of the process. Direct labor was $26,500 and factory overhead was $4,200. The cost of the 2,700 units in process at the end of the period if the first-in, first-out method is used to cost inventories was O a. $6,480 Ob. $7,678 C. $7,079 Od. $6,780