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: Microbiology
HAV is not destroyed by: 
Select and explain. 
A. 0.5 ppm chlorine, B. 1:4000 formalin, C. UV radiation, D. Boiling at 100degC for 5 minutes
A: 0.5 ppm chlorine
Answer: A: 0.5 ppm chlorine 
Explanation: Ans. a. 0.5 ppm chlorine