Darden Corporation uses the weighted-average method in the process costing system. The first processing department the Welding Department, started the month with 18,200 units in its beginning work in process inventory that were 10% complete with respect to conversion costs. The conversion cost in this beginning work in process inventory was $16,700. An additional 85,000 units were started into production during the month. There were 18,000 in the ending work in process inventory of the Welding Department that were 70% complete with respect to conversion costs. A total of $837,880 in conversion costs were incurred in the department during the month. The cost per equivalent unit for the conversion costs for the month is closest to:

A: $8.738

B: $9.965

C: $9.200

D: $8.486