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Department A had 4,100 units in Work in Process that were 78% completed at the beginning of the period at a cost of $7,300. During the period, 32,700 units of direct materials were added at a cost of $68,670, and 34,300 units were completed. At the end of the period, 2,500 units were 28% completed. All materials are added at the beginning of the process. Direct labor was $28,000 and factory overhead was $5,400. The cost of the 2,500 units in process at the end of the period if the first-in, first-out method is used to cost inventories was Oa. $6,720 Ob. $5,250 Oc. $5,985 Od. $5,618