The debits to Work in Process$$Assembly Department for May,

together with data concerning production, are as follows: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 isa.$$2\mathrm{.}54$b$.$$$3\mathrm{.}03$c$.$$$3\mathrm{.}83$d$.$$$2\mathrm{.}21$