**Core Concept**
Tricyclic antidepressants (TCAs) are a class of medications used to treat various psychiatric conditions, including obsessive-compulsive disorder (OCD). TCAs work by inhibiting the reuptake of norepinephrine and serotonin, thereby increasing the concentration of these neurotransmitters in the synaptic cleft.

**Why the Correct Answer is Right**
The correct answer is a TCA that has been specifically used in the management of OCD. Clomipramine is a TCA that has a strong affinity for the serotonin receptor, which is thought to be involved in the pathophysiology of OCD. By inhibiting the reuptake of serotonin, clomipramine increases the concentration of serotonin in the synaptic cleft, which can help to reduce the symptoms of OCD.

**Why Each Wrong Option is Incorrect**
* **Option A:** Imipramine is a TCA that is primarily used to treat depression and certain types of anxiety disorders, but it is not typically used to treat OCD.
* **Option B:** Amitriptyline is a TCA that is often used to treat depression and certain types of chronic pain, but it is not specifically used to treat OCD.
* **Option C:** Nortriptyline is a TCA that is often used to treat depression and certain types of anxiety disorders, but it is not typically used to treat OCD.

**Clinical Pearl / High-Yield Fact**
Clomipramine is the only TCA that is specifically approved by the FDA for the treatment of OCD, making it a high-yield fact for medical students.

**Correct Answer:** C. Clomipramine