**Core Concept**
Kleptomania is a psychiatric disorder characterized by a recurring inability to resist urges to steal objects that are not needed for personal use or for their monetary value. This behavior is often repetitive and distressing, and the individual may feel a sense of guilt or remorse after the act.

**Why the Correct Answer is Right**
The correct answer, **B. Irresistible desire to steal things**, accurately describes the core feature of kleptomania. Individuals with kleptomania often experience an intense urge to steal, which is not driven by financial need or a desire to possess the object. This urge is often accompanied by a sense of tension or anxiety, and the act of stealing provides a temporary relief from this tension. The stealing behavior is typically not associated with a pattern of antisocial behavior, and the individual may feel remorse or guilt after the act.

**Why Each Wrong Option is Incorrect**
**Option A:** Irresistible desire to set fire is actually known as pyromania, which is a different psychiatric disorder characterized by a recurrent and intentional setting of fires.
**Option C:** Compulsive hair pulling is known as trichotillomania, a psychiatric disorder characterized by a recurring and irresistible urge to pull out one's own hair.
**Option D:** Pathological gambling is a separate psychiatric disorder characterized by a recurring and compulsive urge to gamble, often resulting in significant distress or impairment in social, occupational, or other areas of functioning.

**Clinical Pearl / High-Yield Fact**
Kleptomania is often associated with other psychiatric disorders, such as depression, anxiety disorders, and personality disorders. It is essential to consider a comprehensive psychiatric evaluation to diagnose and treat kleptomania effectively.

✓ Correct Answer: B. Irresistible desire to steal things.