The correct answer is: B. can be rectified and made into good units.
Defectives are products that do not meet the required specifications. They can be caused by a variety of factors, such as human error, machine malfunction, or poor materials. Defectives can be rectified and made into good units by identifying the cause of the defect and taking corrective action. This may involve repairing the defective product, replacing a defective component, or adjusting the manufacturing process.
Option A is incorrect because defectives can be rectified and made into good units. Option C is incorrect because defectives are not a part of the finished product. Option D is incorrect because defectives are not necessarily spoilage. Spoiled products are products that have become unusable due to damage or contamination.