3. PV Corporation uses the weighted average method in its process costing system. This month, the beginning inventory in the first processing department consisted of 800 units. The costs and percentage completion of these units in beginning inventory were: Cost Percent Complete 75% 20% Materials costs Conversion costs $ 15,700 $ 7,700 A total of 8,400 units were started and 7,500 units were transferred to the second processing department during the month. The following costs were incurred in the first processing department during the month: Cost Materials costs $ 186,300 Conversion costs $ 329,800 The ending inventory was 70% complete with respect to materials and 60% complete with respect to conversion costs. How many units are in ending work in process inventory in the first processing department at the end of the month? A) 7,600 B) 900 C) 1,700 D) 1,200