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: Social & Preventive Medicine
In severe heat strain the heat stress index (HIS) is ? 
Select and explain. 
A. 30-Oct, B. 40-60, C. 70-90, D. 100
B: 40-60
Answer: B: 40-60 
Explanation: Ans. is lb' ., 40-60 o HSI 40-60 causes severe heat strain and it is not possible to work comfoably.