This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General, Subject name: Microbiology
Phenol coefficient indicates: 
Select and explain. 
A. Efficacy of a disinfectant, B. Dilution of a disinfectant, C. Quantity of a disinfectant, D. Purity of a disinfectant
A: Efficacy of a disinfectant
Answer: A: Efficacy of a disinfectant 
Explanation: Ans. is 'a' i.e., Efficacy of a disinfectant Phenoliccoefficientofatestdisinfectant=PhenolthatkillsS.Typhiinagivensametime (Highestdilution)DisinfectantthatkillsS.typhiinagiventime (Highestdilution)