During December, Krause Chemical Company had the following selected data concerning the manufacture of Xyzine, an industrial cleaner: Production Flow Completed and transferred to the next department Add: Ending work in process inventory Total units to account for Less: Beginning work in process inventory Units started during December Physical Units 100 10 (40% complete as to conversion) 110 20 (60% complete as to conversion) 90 All materials are added at the beginning of processing in this department, and conversion costs are added uniformly during the process. The beginning work in process inventory had $120 of raw materials and $180 of conversion costs incurred. Materials added during December were $540, and conversion costs of $1,484 were incurred. Krause uses the first-in, first-out (FIFO) process cost method. The equivalent units of production used to compute conversion costs for December were: Oa. 110 units. Ob. 104 units. c. 100 units. Od. 92 units.