Department W had 2,160 units, one-third completed at the beginning of the period; 12,900 units were transferred to Department X from Department W during the period; and 1,000 units were one-half completed at the end of the period. Assume the completion ratios apply to direct materials and conversion costs. What is the total number of units to be assigned cost on the cost of production report for Department W?

a. 14,060 units b. 13,900 units c. 12,900 units d. 15,060 units