**Core Concept**
The patient is presenting with symptoms of alcohol withdrawal, specifically delirium tremens (DTs), which is a severe and potentially life-threatening condition that requires prompt medical attention. Delirium tremens typically occurs 48-72 hours after the last drink in individuals with a history of chronic and heavy alcohol use.

**Why the Correct Answer is Right**
The patient's symptoms, including coarse tremors, visual hallucinations, and disorientation to time, are characteristic of delirium tremens. Benzodiazepines, such as chlordiazepoxide, are the first-line treatment for alcohol withdrawal and delirium tremens due to their efficacy in reducing symptoms and preventing seizures. Chlordiazepoxide works by enhancing the effect of gamma-aminobutyric acid (GABA) at the GABA_A receptor, which helps to stabilize the neuronal membrane and reduce excitatory neurotransmission.

**Why Each Wrong Option is Incorrect**
**Option A:** Phenobarbitone is a barbiturate that can be used to manage seizures but is not the first-line treatment for delirium tremens due to its potential for dependence and respiratory depression.
**Option B:** Haloperidol is an antipsychotic that can be used to manage agitation and hallucinations but can exacerbate delirium tremens and should be used with caution in this context.
**Option C:** Metronidazole is an antibiotic that is not indicated for the treatment of delirium tremens.

**Clinical Pearl / High-Yield Fact**
Benzodiazepines, such as chlordiazepoxide, should be initiated in a hospital setting for patients with delirium tremens, as they can precipitate respiratory depression and other adverse effects if used inappropriately.

**Correct Answer:** C. Chlordiazepoxide.