Rathburn, Inc. is a service firm that uses process costing. The firm worked on a total of 1,200 cases this month, 900 of which were completed during the period. The remaining cases were 45% complete. The firm incurred $274,650 in direct labor and manufacturing overhead costs during the period, and had $4,800 in direct labor and manufacturing costs in beginning inventory. Using the weighted average method, what was the total cost of cases completed during the period?

a) 36,450

b) 371,700

c) 37,170

d) 243,000