**Core Concept**
Ezogabine is a novel antiepileptic drug that works by activating a specific type of potassium channel, known as the KCNQ2-5 potassium channel. This channel is responsible for the M-current in the brain, which helps regulate neuronal excitability.

**Why the Correct Answer is Right**
Ezogabine's mechanism of action involves binding to and activating the KCNQ2-5 potassium channel, thereby increasing the flow of potassium ions out of the neuron. This hyperpolarization of the neuronal membrane reduces the excitability of neurons and helps prevent the generation of action potentials, ultimately reducing the frequency of seizures. The activation of KCNQ2-5 potassium channels is thought to be responsible for the therapeutic effects of ezogabine in epilepsy.

**Why Each Wrong Option is Incorrect**
**Option A:** Felbamate is an antiepileptic drug that acts by modulating the NMDA receptor, inhibiting GABA transaminase, and blocking voltage-gated sodium channels, but it does not act by opening potassium channels.

**Option B:** Lacosamide is an antiepileptic drug that acts by selectively enhancing slow inactivation of voltage-gated sodium channels, but it does not act by opening potassium channels.

**Option C:** Gabapentin is an antiepileptic drug that acts by binding to the alpha2delta-1 subunit of voltage-gated calcium channels, but it does not act by opening potassium channels.

**Clinical Pearl / High-Yield Fact**
Ezogabine is unique among antiepileptic drugs in its mechanism of action, and its activation of potassium channels may offer a new therapeutic option for patients with epilepsy who have not responded to other treatments.

**✓ Correct Answer: A. Ezogabine**