**Core Concept**
Delirium tremens (DTs) is a severe form of alcohol withdrawal characterized by intense autonomic instability, hallucinations, and altered mental status. It typically occurs 48-72 hours after the last drink in individuals with a history of chronic alcohol use. The pathophysiology of DTs involves an imbalance of neurotransmitters, particularly GABA and glutamate, due to the abrupt cessation of alcohol's depressant effects.

**Why the Correct Answer is Right**
The correct answer is related to the timing of delirium tremens. DTs usually occur 48-72 hours after the last drink in individuals with a history of chronic alcohol use. This is because alcohol's depressant effects on the central nervous system lead to adaptive changes in neurotransmitter function, particularly GABA and glutamate. When alcohol is withdrawn, these adaptations are unmasked, leading to an imbalance of excitatory and inhibitory neurotransmitters.

**Why Each Wrong Option is Incorrect**
**Option A:** Incorrect. Delirium tremens can occur within 24-48 hours after the last drink, especially in individuals with a history of chronic alcohol use.

**Option B:** Incorrect. Delirium tremens is not typically characterized by a gradual onset of symptoms, but rather a sudden and severe presentation.

**Option C:** Incorrect. Delirium tremens is not a specific diagnosis that requires a certain duration of alcohol use, but rather a severe form of alcohol withdrawal that can occur in individuals with a history of chronic alcohol use.

**Clinical Pearl / High-Yield Fact**
Delirium tremens is a medical emergency that requires immediate treatment with benzodiazepines and supportive care. It is essential to recognize the signs and symptoms of DTs, including altered mental status, autonomic instability, and hallucinations, to provide timely and effective treatment.

**Correct Answer: B. Delirium tremens is not typically characterized by a gradual onset of symptoms, but rather a sudden and severe presentation.**