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: Biochemistry
Quaernary ammonium compound disinfectants are ? 
Select and explain. 
A. Anionic, B. Cationic, C. Neutral, D. Gases
B: Cationic
Answer: B: Cationic 
Explanation: Quaternary ammonium compounds are cationic detergents. They have microcidal and viricidal activities. They can be used for instrument disinfection and skin antisepsis.