given solution plese

Harper Corp uses a process costing system where direct materials are added at the beginning of the process and conversion costs are incurred uniformly throughout the process. Beginning inventory for February consisted of 1,000 units that were 50% completed. During February, 12,000 units were started into the process. On February 28, the inventory consisted of 700 units that were 80% completed. What would be the equivalent units for direct materials cost using the weighted average method? (a) 13,000 (b) 13,500 (c) 14,000 (d) 14,700