Department A had 4,600 units in Work in Process that were 63% completed at the beginning of the period at a cost of $7,800. During the period, 30,500 units of direct materials were added at a cost of $64,050, and 32,300 units were completed. At the end of the period, 2,800 units were 22% completed. All materials are added at the beginning of the process. Direct labor was $25,000 and factory overhead was $5,800. The cost of the 2,800 units in process at the end of the period if the first-in, first-out method is used to cost inventories was: a. $7,144, b. $6, 512, c. $5,880, d. $6,196