**Core Concept**
A triphasic withdrawal syndrome is characterized by distinct stages of physical and psychological symptoms that occur when an individual abruptly discontinues the use of a particular substance. This phenomenon is associated with certain substances that induce significant physiological dependence.

**Why the Correct Answer is Right**
Cocaine is a potent stimulant that causes significant physiological dependence, leading to a triphasic withdrawal syndrome upon abrupt discontinuation. The three phases of withdrawal include:
- **Crash phase**: Characterized by intense fatigue, depression, and sleep disturbances, which occur within 24 hours after the last use.
- **Withdrawal phase**: Marked by irritability, anxiety, and restlessness, which typically peaks within 2-4 days.
- **Extinction phase**: Characterized by a gradual return to normal physiological and psychological functioning, which may take several weeks to months.

The triphasic withdrawal syndrome in cocaine users is thought to be mediated by the depletion of dopamine and norepinephrine stores in the brain, as well as the disruption of normal sleep patterns.

**Why Each Wrong Option is Incorrect**
* **Option A:** Alcohol withdrawal typically presents with a biphasic syndrome, characterized by a severe acute withdrawal phase followed by a less severe post-acute withdrawal syndrome.
* **Option B:** LSD (lysergic acid diethylamide) is a hallucinogenic drug that does not induce significant physiological dependence, and its withdrawal is not typically associated with a triphasic withdrawal syndrome.
* **Option C:** Heroin withdrawal presents with a distinct set of symptoms, including anxiety, agitation, and severe physical discomfort, but it does not exhibit a triphasic withdrawal syndrome like cocaine.

**Clinical Pearl / High-Yield Fact**
A memorable way to recall the triphasic withdrawal syndrome associated with cocaine is to remember the acronym **CRASH**, which stands for:
- C: Crash phase (intense fatigue, depression, and sleep disturbances)
- R: Restlessness and irritability during the withdrawal phase
- A: Anxiety and agitation
- S: Sleep disturbances
- H: Hypertension and hyperthermia (may occur during the withdrawal phase)

**✓ Correct Answer: D. Cocaine**