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: Pathology
Salivary secretion becomes zero at: 
Select and explain. 
A. >30 Gray, B. >60 Gray, C. >40 Gray, D. >50 Gray
B: >60 Gray
Answer: B: >60 Gray 
Explanation: None