How do I find the equivalent units for conversion costs?

The following information is provided by Zander Corporation: WIP Inventory, January 1 Units started Units completed and transferred out WIP Inventory, December 31 Direct materials Direct labor Manufacturing Overhead 0 units 12,300 8,100 4,200 $28,200 $18,000 $7,500 The units in ending WIP Inventory were 80% complete for materials and 74% complete for conversion costs. At the end of the year, what are the equivalent units for conversion costs? O A. 9,102 OB. 8,100 OC. 3,108 OD. 11,208