This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General Microbiology Pa-2 and Pa-3 (Sterilization and Bacterial Genetics), Subject name: Microbiology
Sputum can be disinfected by all except 
Select and explain. 
A. Autoclaving, B. Chlorhexidine, C. Boiling, D. Cresol
B: Chlorhexidine
Answer: B: Chlorhexidine 
Explanation: Autoclaving is the safest and most effective method for sputum disinfection Incineration is an effective alternative. Boiling used after an initial disinfection by 5% phenol (carbolic acid) or its derivatives like Lysol and Cresol.