This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Radiotherapy, Subject name: Radiology
The least radio sensitive tissue is - 
Select and explain. 
A. Nervous tissue, B. Bone, C. Kidney, D. Thyroid
A: Nervous tissue
Answer: A: Nervous tissue 
Explanation: Human Cell Radiation Sensitivity High Lymphocytes (white blood cells) Spermatogonia (sperm-producing cells) Erythroblasts (immature red blood cells) Intestinal crypt cells (small intestine) Mid Spermatids (non-dividing immature sperm) Osteoblasts (immature bone cells) Low Muscle cells Nerve cells