Oman Corporation uses the FIFO method in its process costing system. Information for the month of September appear below: Fi Percentage complete with Units respect to conversion Beginning WIP 15,000 20% Completed and Transferred out 80,000 Ending WIP 24,000 90% According to the company's records, the conversion cost in beginning work in process inventory was $15,660 at the beginning of September. Additional conversion costs of $526,524 were incurred in the department during the month. The cost per equivalent unit for conversion costs for September is closest to: (Round off to three decimal places.) a. $5.916 b. $5.340 c. $5.220 d. $5.213