According to the cited reference, of the given options, the Retina scan has the lowest user acceptance level as it is needed for the user to get his eye close to a device and it is not user friendly and very intrusive.
However, retina scan is the most precise with about one error per 10 millions usage.
Look at the 2 tables below. If necessary right click on the image and save it on your desktop for a larger view or visit the web site directly at https://sites.google.com/site/biometricsecuritysolutions/crossover-… . Biometric Comparison Chart


Biometric Aspect Descriptions
Reference(s) used for this question:
RHODES, Keith A., Chief Technologist, United States General Accounting Office, National Preparedness, Technologies to Secure Federal Buildings, April 2002 (page 10). and https://sites.google.com/site/biometricsecuritysolutions/crossover-…