**Core Concept**
The question tests the knowledge of severe withdrawal syndromes associated with psychotropic medications. This concept is crucial in managing patients on long-term medication and understanding the risks of abrupt discontinuation.

**Why the Correct Answer is Right**
The correct answer is **B. Benzodiazepines**. Benzodiazepines, such as alprazolam, clonazepam, and diazepam, can cause severe withdrawal symptoms when suddenly discontinued due to their sedative and hypnotic effects. The withdrawal syndrome, also known as benzodiazepine withdrawal syndrome, can manifest with symptoms like anxiety, insomnia, tremors, seizures, and in severe cases, psychosis. This is because benzodiazepines lead to physical dependence by affecting the GABA receptor, a key neurotransmitter involved in regulating sleep, anxiety, and muscle relaxation.

**Why Each Wrong Option is Incorrect**
* **Option A:** Antidepressants, such as selective serotonin reuptake inhibitors (SSRIs), can cause withdrawal symptoms like dizziness, nausea, and headache, but they are typically not as severe as those seen with benzodiazepine withdrawal.
* **Option C:** Antipsychotics, such as haloperidol, can cause withdrawal symptoms like akathisia and dystonia, but these are generally not as severe as the withdrawal symptoms associated with benzodiazepines.
* **Option D:** Lithium, a mood stabilizer, can cause withdrawal symptoms like tremors and confusion, but these are generally not as severe as those seen with benzodiazepine withdrawal.

**Clinical Pearl / High-Yield Fact**
When discontinuing benzodiazepines, it is essential to taper the dose gradually over a period of weeks to minimize the risk of severe withdrawal symptoms.

**Correct Answer: B. Benzodiazepines**