Priya accidently placed her hand over a flame and immediately pulled it back. She felt the sensation of heat and reacted due to the action of

Question

$\begin{array}{1 1} (a)\; \text{Blood cells } \\ (b)\;\text{Nerve cells} \\ (c)\; \text{Skin surface} \\ (d)\; \text{Nucleus of the cell} \end{array}$