**Core Concept**
Lidocaine is a local anesthetic and antiarrhythmic medication that works by blocking sodium channels in the nervous system. Its pharmacological effects are primarily due to its ability to inhibit the influx of sodium ions into neurons, leading to a decrease in neuronal excitability.

**Why the Correct Answer is Right**
Lidocaine's mechanism of action involves the blockade of voltage-gated sodium channels, specifically the fast sodium channels (Nav1.5) in cardiac tissue. This blockade prevents the rapid depolarization of the cardiac action potential, thereby reducing automaticity and conduction velocity in the heart. In local anesthesia, lidocaine's sodium channel blockade prevents the initiation and propagation of action potentials in sensory neurons, leading to a loss of sensation in the affected area.

**Why Each Wrong Option is Incorrect**
**Option A:**
* Not enough information provided to determine why this option is incorrect.

**Option B:**
* This statement is not universally true; lidocaine's effects are generally dose-dependent, and its duration of action can vary depending on the specific formulation and administration route.

**Option C:**
* Lidocaine does indeed have a role in the treatment of ventricular arrhythmias, particularly in the setting of acute myocardial infarction. However, its use in this context is often limited by its potential for systemic toxicity.

**Option D:**
* Lidocaine is indeed metabolized by the liver, specifically by the cytochrome P450 enzyme system, and its clearance can be affected by various factors, including liver function and concurrent medication use.

**Clinical Pearl / High-Yield Fact**
It's essential to note that lidocaine's effects can be potentiated by the concurrent use of beta-blockers, which can further reduce cardiac automaticity and conduction velocity.

**Correct Answer: D. Lidocaine is metabolized by the liver.**