正解:B
This is because a palm scanner is a type of biometric security method that uses the physical characteristics of a person's palm, such as the shape, size, and vein patterns, to authorize access to a location. A palm scanner is more reliable and secure than other methods, such as a PIN pad or a digital card reader, which can be easily stolen, lost, or shared. A palm scanner is also more hygienic and convenient than other biometric methods, such as a fingerprint scanner or a facial recognition system, which can be affected by dirt, oil, or lighting conditions. The source of this answer is the Cisco ENCOR v1.1 course, module 2, lesson 2.2: Implementing Device Access Control.