Deprivation refers to:

A) the behavior being modified.
B) withholding a reinforcer for a period of time in order to increase the effectiveness of the  reinforcer.
C) the gradual removal of discriminative stimuli.
D) the response being combined with reinforcers from a behavioral chain.

Deprivation

A period of time prior to a training session during which an individual does not experience the reinforcer in order to increase the reinforcer's effectiveness.

Reinforcer

Any stimulus that strengthens or increases the likelihood of a specific response or behavior by being presented immediately after that response or behavior.

Effectiveness

The degree to which a method, intervention, or action achieves its intended outcome or result.