This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Environment and Health, Subject name: Social & Preventive Medicine
Concentration of bleaching powder used for disinfection oi urine and faeces is 
Select and explain. 
A. 5%, B. 10%, C. 15%, D. 20%
A: 5%
Answer: A: 5% 
Explanation: 108) Ans: a (5%) Ref: Park 20th ed pi 18Concentration of bleaching powder used for disinfection of faeces anc urine is 5%.Agents suitable for disinfection of faeces and urineDisinfectantAmount per literConcentrationBleaching powder50 g5%Crude phenol100 ml10%Cresol50 ml5%Fonnalin100ml10%