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
What strength of phenol may be used for disinfection of faeces? 
Select and explain. 
A. 1%, B. 2.50%, C. 5%, D. 10%
D: 10%
Answer: D: 10% 
Explanation: Usage of phenol Recommended strength Decontamination of faeces 10% Mopping of floor and cleaning of drains 5% Bacteriostatic 0.5% Ref : Park 21st edition, page 117