Department A had 4,500 units in work in process that were 74% completed as to labor and overhead at the beginning of the period, 25,800 units of direct materials were added during the period, 27,800 units were completed during the period; and 2,500 units were 40% completed as to labor and overhead at the end of the period. All materials are added at the beginning of the process. The first-in, first-out method is used to cost inventories. The number of equivalent units of production for material costs for the period was a. 30,300 X b, 23,300 c. 27,800 d. 25,800