Department R had 4,600 units in work in process that were 70% completed as to labor and overhead at the beg units of direct materials were added during the period; 30,300 units were completed during the period; and 2,90 to labor and overhead at the end of the period. All materials are added at the beginning of the process. The first cost inventories. The number of equivalent units of production for conversion costs for the period was Oa. 32,637 Ob. 28,037 Oc. 30,300 Od. 37,800 Department R had 4,600 units in work in process that were 70% completed as to labor and overhead at the beginning of the period; 28,600 units of direct materials were added during the period: 30,300 units were completed during the period; and 2,000 units were 33% 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 conversion costs for the period was a. 32.637 Ob 20.037 Oc. 30.300 d. 37.800