The Martin Rubber Company Produces Tires

The Martin Rubber Company produces tires. The following information is available for Martin:
Beginning work in process inventory: 2,000 tires, 100% complete for direct materials, 60% complete for conversion costs, cost of direct materials = $12,000, cost of direct labor and manufacturing overhead allocated = $10,000 Current period activity: 12,600 tires completed, cost of direct materials added = $300,950, cost of direct labor and manufacturing overhead allocated = $232,980 Ending work in process inventory: 4,500 units, 100% complete for direct materials, 40% complete for conversion costs What were the equivalent units of production for conversion costs?

A) 14,400
B) 13,200
C) 15,600
D) 13,600