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: Microbiology
All are true regarding propeies of common disinfectants, EXCEPT: 
Select and explain. 
A. Glutaraldehyde is sporicidal, B. Hypochlorites are viricidal, C. Alcohol is fungicidal, bactericidal not sporicidal, D. Phenol usually requires organic matter to act
D: Phenol usually requires organic matter to act
Answer: D: Phenol usually requires organic matter to act 
Explanation: Phenol and its derivatives acts by denaturing proteins, especially in cell membrane. It is active aginst gram positive bacteria but its activity is reduced in presence of organic matter. Glteraldehyde is considered a chemical sterilant since it has a broad spectrum of activity inluding being sporicidal. It acts by alkylating microorganism proteins. Hypochlorites are bactericidal, myocabactericidal, fungicidal and virucidal. Alcohols are among the most widely used disinfectant and antiseptic. They are bactericidal and fungicidal not sporicidal. They are also effective against some lipid containing viruses.