**Core Concept**
Lathyrus sativa, also known as grass pea or chickling pea, is a legume that contains a toxic compound responsible for neurolathyrism, a motor neuron disease. The active principle in Lathyrus sativa is a non-protein amino acid that plays a crucial role in its toxicity.

**Why the Correct Answer is Right**
The active principle in Lathyrus sativa is ODAP (oxalyldiaminopropionic acid), a non-protein amino acid that acts as a glutamate receptor antagonist. This leads to an excitotoxicity-mediated damage to the motor neurons, resulting in neurolathyrism. ODAP is a potent inhibitor of glutamate uptake, causing an excessive accumulation of glutamate in the synaptic cleft, which ultimately leads to neuronal damage.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect as it does not mention the correct active principle of Lathyrus sativa.
* **Option B:** This option is incorrect as it is not a known compound associated with the toxicity of Lathyrus sativa.
* **Option C:** This option is incorrect as it is not a recognized compound related to the active principle of Lathyrus sativa.

**Clinical Pearl / High-Yield Fact**
It is essential to note that neurolathyrism can occur when Lathyrus sativa is consumed in large quantities over a prolonged period, often in times of famine or food scarcity. The disease is characterized by progressive motor weakness, paralysis, and eventually, death.

**Correct Answer:** C. ODAP (oxalyldiaminopropionic acid)