Luft Company uses the weighted-average method in its process costing system. Operating data for the first processing department for the month of June appear below. Units Percent Complete with respect to conversion Beginning work in process inventory 11,000 90% Started in production during June 58,000 Ending work in process inventory 17,000 10% According to the company's records, the conversion cost in beginning work in process inventory was $79,893 at the beginning of June. Additional conversion costs f $343,830 were incurred in the department during the month. Wha was the cost per equivalent unit for conversion costs for the month? a. $8,070 b. $7,891 c. $5,928 d. $4,584