The debits to Work in ProcessAssembly Department for April, together with data concerning production, are as follows:

April 1, work in process:
Materials cost, 3,000 units	$ 7,939
Conversion costs, 3,000 units, 40% completed	5,112
Materials added during April, 10,000 units	27,796
Conversion costs during April	32,567
Goods finished during April, 12,000 units	0
April 30 work in process, 1,000 units, 40% completed	0

All direct materials are added at the beginning of the process, and the first-in, first-out method is used to cost inventories. The conversion cost per equivalent unit for April is

a.$2.91

b.$2.51

c.$3.26

d.$2.83