The correct answer is: B. rectified
Defectives are that portion of production which can be rectified at some extra cost of re-operation. This means that they can be fixed or repaired, but it will cost more money to do so than it would have cost to produce them correctly in the first place.
Option A, sold, is incorrect because defective products are not usually sold. They may be sold at a discount, but they are often scrapped or recycled.
Option C, purchased, is incorrect because defective products are not usually purchased. They may be purchased by companies that specialize in repairing or recycling them, but they are not usually purchased by consumers.
Option D, None of these, is incorrect because rectified is the only option that is consistent with the definition of defectives.