An outpatient substance abuse clinic provides vouchers to clients who have a negative urine drug screen. This is an example of which of the following?

Choice A reason: Contingency management is a behavioral intervention that uses tangible rewards to reinforce positive behaviors, such as abstinence. Providing vouchers for clean drug screens is a classic example of this approach. Choice B reason: Operant conditioning is the broader framework under which contingency management falls. While technically correct, it is less specific than contingency management in this context. Choice C reason: Cognitive learning involves acquiring knowledge and understanding through thought, experience, and the senses. It does not involve external rewards for behavior. Choice D reason: Stimulus discrimination refers to the ability to distinguish between different stimuli and respond appropriately. It is not relevant to the reward-based system described.