**Core Concept**
Indifferent fibres refer to a type of nerve fibre that is neither sensory nor motor in function. They are intermediate fibres that can potentially develop into either sensory or motor fibres, depending on the presence of a trophic stimulus.

**Why the Correct Answer is Right**
Indifferent fibres are thought to be the precursors to both sensory and motor neurons. They have the ability to differentiate into either type of neuron, depending on the signals they receive from the environment. This process is influenced by the presence of specific growth factors and trophic stimuli. For example, the presence of nerve growth factor (NGF) can direct indifferent fibres to develop into sensory neurons, while the presence of brain-derived neurotrophic factor (BDNF) can direct them to develop into motor neurons.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because indifferent fibres are not a type of fibre that is involved in the transmission of pain signals.
* **Option B:** This option is incorrect because indifferent fibres are not a type of fibre that is involved in the control of voluntary movements.
* **Option C:** This option is incorrect because indifferent fibres are not a type of fibre that is involved in the transmission of autonomic signals.

**Clinical Pearl / High-Yield Fact**
It's worth noting that indifferent fibres play a critical role in the development of the nervous system, and their differentiation into sensory and motor neurons is a complex process that is influenced by a variety of genetic and environmental factors.

**Correct Answer:** C.