. Marten Corporation uses the FIFO method in its process costing system. Operating data for the Casting Department for the month of September appear below. According to the company's records, the conversion cost in beginning work in process inventory was $83,600 at the beginning of September. Additional conversion costs of $427,682 were incurred in the department during the month. What is the cost per equivalent unit for conversion costs for September closest to? Round off to three decimal places. A. $5.620 B. $5.779 C. $5.498 D. $5.500