Final answer:
Interneurons link sensory neurons to motor neurons and are located in the grey matter of the central nervous system, making the correct answer (c).
Step-by-step explanation:
The purpose of interneurons is to serve as a link between sensory neurons (afferent neurons) and motor neurons (efferent neurons), facilitating communication within the central nervous system. These interneurons are located in the grey matter, which is composed of neuron and glial cell bodies and is distinguished from the myelinated axons of the white matter. Therefore, interneurons play a crucial role in the processing and relaying of signals within the grey matter of the spinal cord and brain.
Based on the provided information, the correct answer to the student's question is (c) Links afferent and efferent neurons in the grey matter.