LICHOSI S essionLocator Bunprogress=false Department A had 4,300 units in work in process that were 77% completed as to labor and overhead at the beginning of the period; 28,600 units of direct materials were added during the period; 30,100 units were completed during the period; and 2,800 units were 29% 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 Oa. 25,800 Ob. 32,900 Oc. 28,600 Od. 30,100