**Core Concept:** Neurolathyrism is a neurological disorder caused by consuming a toxic protein found in the seeds of some legumes, primarily from the family of Leguminosae. The condition leads to progressive spastic paralysis due to axon degeneration and demyelination in the motor neurons.

**Why the Correct Answer is Right:** Neurolathyrism is caused by consuming a toxic protein called oxalyldiamines, specifically α-Oxaloacetate Semialdehyde (OA-SA) and β-Oxaloacetate Semialdehyde (OA-SA). These compounds can cross the blood-brain barrier and cause damage to motor neurons, leading to spastic paralysis.

**Why Each Wrong Option is Incorrect:**

A. Lathyrism is not caused by consuming legumes in general. The correct answer refers to specific legumes from the family Leguminosae, which contain toxic oxalyldiamines.

B. Although legumes may cause other neurological disorders, this option does not address the unique mechanism of neurolathyrism caused by oxalyldiamines.

C. Neurolathyrism is not limited to agricultural labourers; however, this option focuses on the occupation of the patient rather than the toxic substance and its mechanism of action.

D. Neurolathyrism is not solely caused by consuming beans; it is caused by specific legumes from the family Leguminosae and their toxic oxalyldiamines.

**Clinical Pearl:** Neurolathyrism serves as a reminder of the importance of food safety and proper preservation methods to prevent consumption of toxic substances. This is particularly relevant in areas where these specific legumes are common due to agricultural practices or dietary habits.

In conclusion, the correct answer is 'D' because the toxic protein causing neurolathyrism, α-Oxaloacetate Semialdehyde and β-Oxaloacetate Semialdehyde, are found in legumes from the family Leguminosae.