The debits to Work in Process-Assembly Department for May, together with data concerning production, are as follows: May 1, work in process: $8,900 Materials cost, 3,000 units Conversion costs, 3,000 units, 50% completed Materials added during May, 10,000 units 5,000 28,000 Conversion costs during May 34,000 Goods finished during May, 11,500 units 0 May 31 work in process, 1,500 units, 50% completed 0 All direct materials are placed in process at the beginning of the process, and the first-in, first-out method is used to cost inventories. The materials cost per equivalent unit for May is a. $2.80 b. $3.40 c. $2.43 d. $4.29