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: Radiology
Least radiosensitive among the following is: 
Select and explain. 
A. RBC, nerve, muscle , epithelial cells, B. Endothelial cells, bone cells, C. Nerve, muscle, bone, D. All of the above
A: RBC, nerve, muscle , epithelial cells
Answer: A: RBC, nerve, muscle , epithelial cells 
Explanation: None