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
Disinfecting action of chlorine on water is mainly due to 
Select and explain. 
A. Hydrogen chloride, B. Hydrogen ions, C. Hypochlorous acid, D. Hypochlorite ions
C: Hypochlorous acid
Answer: C: Hypochlorous acid 
Explanation: None