Which of the following is a deficiency of process costing?

a.	In process costing, decision makers are informed about the average cost of the units, but not the actual cost of each particular unit or job.
b.	In process costing, firms accumulate costs in a department or production process during the accounting period, then spread those costs evenly over the units produced that period, computing an average unit cost.
c.	Process costing does not require as much record keeping as job costing system because it does not require keeping track of the cost of each job.
d.	None of the answers is a deficiency.