Which of the following statements is FALSE about spoilage costs?

a) For external financial reporting purposes, normal spoilage costs should be reported as a separate expense item in the income statement.

b) Regardless of the accounting treatment and computation, it is usually desirable to internally report spoilage costs as a separate item for management purposes.

c) Normal spoilage is expected as a natural outcome of an imperfect process and added back to the cost of good units produced.

d) The % of completion for spoiled units depends on when the spoilage is detected and what portion of the work has been completed for those units.