**Question:** Behaviour therapy to change maladaptive behavior using the response as reinforcer uses the principles of-

A. Reinforcement
B. Punishment
C. Desensitization
D. Habituation

**Core Concept:**
Behaviour therapy is a psychological treatment approach that focuses on changing undesirable or problematic behavior patterns. In this context, reinforcers are used to enhance or encourage desired behavior, and punishers are used to discourage undesirable behavior.

**Why the Correct Answer is Right:**
The correct answer is A: Reinforcement. In behavior therapy, reinforcers are positive stimuli that increase the likelihood of a particular behavior occurring again. By using the response itself as the reinforcer, the individual is more likely to repeat the desired behavior, thus changing their maladaptive behavior.

**Why Each Wrong Option is Incorrect:**
Option B: Punishment - Punishment is the introduction of aversive stimuli to decrease the likelihood of a particular behavior occurring again. In behavior therapy, punishers are not used in the same way, as they may not be effective in changing the behavior.

Option C: Desensitization - Desensitization is a specific technique used in exposure therapy to reduce fear or anxiety by gradually exposing the patient to the feared stimulus or situation. It is not the same as using the response itself as a reinforcer in behavior therapy.

Option D: Habituation - Habituation is a process where a response decreases in frequency as a consequence of repeated presentation of the same stimulus. It is not related to behavior therapy principles of reinforcing or punishing behaviors.

**Clinical Pearl:**
Understanding the difference between reinforcement and punishment is essential in behavior therapy. Reinforcement focuses on increasing the likelihood of desired behavior, whereas punishment aims to decrease the likelihood of undesirable behavior. In behavior therapy, reinforcers are used to change maladaptive behavior by increasing the likelihood of the desired behavior.