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: Surgery
Best skin disinfectant for central line inseion is: 
Select and explain. 
A. Povione iodine, B. Alcohol, C. Cetrimide, D. Chlorhexidine
D: Chlorhexidine
Answer: D: Chlorhexidine 
Explanation: Ans is 'd' i.e. Chlorhexidine "Chlorhexidine is now the disinfectant recommended for all catheter placement procedures and for routine site cleansing during dressing changes."- Comprehensive Hospital Medicine: An Evidence-Based And Systems Approach By Mark V. Williams, Scott A. Flanders, p320 "Use of antiseptic solution for skin disinfection at the catheter inseion site helps prevent catheter-related infection. Chlorhexidine-based solutions appear to be superior to both aqueous and alcohol-based povidone-iodine in reducing the risk for catheter colonization and catheter-related bloodstream infection. If there is a contraindication to chlorhexidine, tincture of iodine, an iodophor or 70 percent alcohol can be used as alternatives"-uptodate.com