**Core Concept:** Angel Dust is a colloquial term for the synthetic stimulant drug called Phencyclidine (PCP). PCP is an analgesic, anti-inflammatory, and anticonvulsant agent, commonly used in veterinary medicine for analgesia and anesthesia in animals.

**Why the Correct Answer is Right:** Angel Dust is the street name for Phencyclidine, a drug used mainly for its psychoactive properties. PCP acts as a dissociative anesthetic, disrupting the normal integration of sensory, motor, and cognitive functions. It alters the perception of time, space, and self, causing delirium, hallucinations, and aggressive behavior.

**Why Each Wrong Option is Incorrect:**

A. Diphenylhydantoin (Felbatol) - This is an anticonvulsant drug used to treat epilepsy and not associated with the term "Angel Dust."

B. Phenothiazines (e.g., chlorpromazine) - These are a class of antipsychotic drugs used in the treatment of schizophrenia and other psychiatric disorders, not known for the term "Angel Dust."

C. Morphine - Morphine is an opioid analgesic used to manage severe pain, not associated with the term "Angel Dust."

D. Phencyclidine (PCP) - As mentioned above, PCP is the correct answer, known for its psychoactive properties and the street name "Angel Dust."

**Clinical Pearl / High-Yield Fact:** Phencyclidine (PCP) is a Schedule II controlled substance in the US due to its potential for abuse and high potential for dependence and addiction. It is crucial for medical students to be aware of the dangers of such substances and the potential adverse effects of illicit drugs.