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
The most sensitive cell cycle stage for radiotherapy is: 
Select and explain. 
A. S phase, B. G1, C. G2, D. G2M
D: G2M
Answer: D: G2M 
Explanation: Ans. G2M