**Core Concept**
Tremors during alcohol withdrawal are due to a sudden decrease in the inhibitory effects of gamma-aminobutyric acid (GABA) in the brain, leading to an overactivation of the central nervous system. This disruption in GABAergic neurotransmission results in the characteristic tremors and other autonomic symptoms associated with alcohol withdrawal.

**Why the Correct Answer is Right**
Tremors are a classic symptom of alcohol withdrawal, often occurring within 5-10 hours after the last drink. This is because chronic alcohol consumption leads to downregulation of GABA receptors and an increase in the activity of glutamate, a neurotransmitter that is excitatory. When alcohol is suddenly withheld, the inhibitory effects of GABA are diminished, allowing glutamate to dominate, resulting in tremors, anxiety, and other symptoms. The severity of tremors can be managed with benzodiazepines, which enhance GABA activity and help stabilize the nervous system.

**Why Each Wrong Option is Incorrect**
**Option A:** Bodyache is not a specific symptom of alcohol withdrawal, although patients may experience generalized musculoskeletal discomfort due to dehydration or electrolyte imbalances. However, bodyache is not a characteristic feature of alcohol withdrawal.
**Option C:** Diarrhea may occur in some cases of alcohol withdrawal, especially if the patient has a history of gastrointestinal problems or is experiencing autonomic instability. However, diarrhea is not the most common symptom of alcohol withdrawal.
**Option D:** Rhinorrhea (runny nose) is not a typical symptom of alcohol withdrawal. While patients may experience various autonomic symptoms, rhinorrhea is not a characteristic feature of this condition.

**Clinical Pearl / High-Yield Fact**
When managing patients with alcohol withdrawal, it's essential to remember that benzodiazepines are the first-line treatment for preventing seizures and reducing symptoms. However, when using benzodiazepines, it's crucial to be aware of the risk of respiratory depression, especially in patients with a history of chronic alcohol use.

✓ Correct Answer: B. Tremor