**Core Concept**
Strychnine is a potent neurotoxin that acts by interfering with the inhibitory neurotransmission in the central nervous system (CNS). It primarily targets the glycine receptors, which are responsible for mediating the inhibitory effects of glycine in the spinal cord and brainstem.

**Why the Correct Answer is Right**
Strychnine acts by competitively inhibiting the glycine receptors, thereby blocking the chloride channels and preventing the influx of chloride ions into the neuronal cells. This results in an increase in the excitatory neurotransmission, leading to hyperexcitability of the neurons and eventual convulsions. The glycine receptors are a type of ligand-gated chloride channel that is responsible for mediating the inhibitory effects of glycine in the CNS.

**Why Each Wrong Option is Incorrect**
**Option A:** Strychnine does not act by inhibiting the GABA receptors, which are also involved in inhibitory neurotransmission in the CNS.
**Option B:** Strychnine does not act by stimulating the acetylcholine receptors, which are involved in excitatory neurotransmission in the CNS.
**Option C:** Strychnine does not act by inhibiting the NMDA receptors, which are involved in excitatory neurotransmission in the CNS.

**Clinical Pearl / High-Yield Fact**
Strychnine poisoning is characterized by muscle stiffness, hyperreflexia, and eventually convulsions, which can be fatal if not treated promptly. The treatment for strychnine poisoning involves supportive care, including administration of activated charcoal and management of convulsions with benzodiazepines.

**Correct Answer: B. Strychnine acts by inhibiting glycine receptors.**