**Core Concept**
Systematic desensitization is a type of behavior therapy that involves gradual exposure to a feared stimulus in a controlled and safe environment to reduce anxiety and promote habituation. This approach is based on the principles of classical conditioning, where a conditioned response to a previously neutral stimulus is reduced over time.

**Why the Correct Answer is Right**
Systematic desensitization is a widely used technique in the treatment of specific phobias, such as fear of spiders, heights, or enclosed spaces. The process involves creating a hierarchy of situations that trigger increasing levels of anxiety, from mildly to severely distressing. The patient is then gradually exposed to each situation, starting with the least anxiety-provoking one, while learning relaxation techniques to manage their anxiety. This allows the patient to become habituated to the feared stimulus and reduces the conditioned response over time.

**Why Each Wrong Option is Incorrect**
**Option A:** While cognitive-behavioral therapy (CBT) is a broader category of therapy that includes systematic desensitization, it is not the most specific or direct answer to this question.
**Option B:** Exposure therapy is a closely related technique to systematic desensitization, but it is not as specific or focused on gradual exposure.
**Option C:** Desensitization can be used in the treatment of other disorders, such as post-traumatic stress disorder (PTSD), but specific phobias are the most common indication for this technique.

**Clinical Pearl / High-Yield Fact**
Systematic desensitization is a highly effective treatment for specific phobias, with success rates ranging from 70% to 90% in controlled studies. This technique is often combined with other therapies, such as CBT, to enhance treatment outcomes.

**Correct Answer: C. Specific phobia. Systematic desensitization is a behavior therapy used in the treatment of specific phobias.**