Answer: Secondary reinforcers may be used to supply primary reinforcers.
Primary reinforcers are those that arise from biological needs. For example, food, drink and pleasure are all primary reinforces. On the other hand, secondary reinforcements are those that are "conditioned." For example, prizes, prestige, money and grades at school. Secondary reinforcements are powerful because of their association with primary ones (for example, you want money because it can help you get food and shelter). Secondary reinforcers, therefore, may be used to supply primary reinforcers.