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: Pharmacology
Nonoxynol 9 ? 
Select and explain. 
A. Is a chemical detergent, B. Is a barrier contraceptive, C. Can be used repeatedly in a day, D. Can be used to prevent STIs
A: Is a chemical detergent
Answer: A: Is a chemical detergent 
Explanation: Ans. is'a'i.e., Is a chemical detergentNonoxynol - 9Chemical detergent that damages the sperm cell membranes, killing the cells.It is a safe, effective contraceptive option for women at low risk of HIV/ STIs