This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Physiology
Which of the following statements is true about thermoreceptor? 
Select and explain. 
A. They are activated only by severe cold or severe heat, B. They are located on superficial layers of the skin, C. They are on dendritic endings of A fibers and C fibers, D. All of the above
D: All of the above
Answer: D: All of the above 
Explanation: Pain and temperature sensations arise from unmyelinated dendrites of sensory neurons located around hair follicles throughout the glabrous and hairy skin as well as deep tissue.