Department R had 4,100 units in work in process that were 77% completed as to labor and overhead at the beginning of the period; 38,700 units of direct materials were added during the period; 40,100 units were completed during the period; and 2,700 units were 32% 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 Oa. 46,900 Ob. 37,807 Oc. 40,100 d. 41,907