The correct answer is: A. cost per good units transferred out.
Total transferred-out cost plus normal spoilage is divided by number of goods units produced to calculate cost per good units transferred out. This is because the cost of goods transferred out is the total cost of the goods that have been completed and transferred to the next department or to finished goods inventory. The cost of normal spoilage is included in the cost of goods transferred out because it is a normal and expected cost of production. The number of goods units produced is the total number of goods that have been produced during the period.
Option B is incorrect because cost per good units transferred in is calculated by dividing the total cost of goods transferred in by the number of goods units transferred in. Option C is incorrect because revenue per good units transferred out is calculated by dividing the total revenue from goods transferred out by the number of goods units transferred out. Option D is incorrect because revenue per good units transferred in is calculated by dividing the total revenue from goods transferred in by the number of goods units transferred in.