Elite Company uses the weighted-average method in its process costing system. The company had 2,000 units in work in process at April 1, that were 60% complete with respect to conversion cost. During April, 15,000 units were completed. At 30 April 5,000 units remained in work in process and they were 40% complete with respect to conversion cost. Direct materials are added at the beginning of the process. How many units were started during April? Select one: a. 15000 b. 18000 c. 5000 d. 20000